Ion migration critically underpins the operational instability of metal halide perovskites, yet the fundamental mechanisms by which defect chemistry and physics govern ion migration in mixed-halide perovskites, and their critical role in driving the distinct instability pathways under dark versus illuminated conditions, remain inadequately understood. Here, we investigate ion-migration dynamics coupled with defect and phase segregation in FAPb(I1–xBrx)3, uncovering a defect-governed evolution of ion migration across different Br compositions. Under dark conditions, ion migration is revealed to be dominated by the specific characteristics of halide interstitial defects, whereas illumination triggers FA-cation migration that strongly correlates with the deep-level defect density. Despite exhibiting comparable halide-migration barriers, high-Br compositions undergo a two-state phase segregation process, comprising an initial thermodynamically driven halide separation followed by a kinetically accelerated regime facilitated by a substantial reduction in the halide migration barrier. These findings provide essential insights for stabilizing wide-bandgap perovskites in high-efficiency tandem photovoltaics.
{"title":"Mechanistic insights into defect-governed ion migration and phase instability in mixed-halide perovskites","authors":"Yueran Xiang, Haimeng Xin, Chenyu Wang, Fuyi Zhou, Hengyu Zhang, Pengjie Hang, Lingbo Xu, Xuegong Yu, Jingjing Xue, Deren Yang, Zhenyi Ni","doi":"10.1039/d5ta10296k","DOIUrl":"https://doi.org/10.1039/d5ta10296k","url":null,"abstract":"Ion migration critically underpins the operational instability of metal halide perovskites, yet the fundamental mechanisms by which defect chemistry and physics govern ion migration in mixed-halide perovskites, and their critical role in driving the distinct instability pathways under dark <em>versus</em> illuminated conditions, remain inadequately understood. Here, we investigate ion-migration dynamics coupled with defect and phase segregation in FAPb(I<small><sub>1–<em>x</em></sub></small>Br<small><sub><em>x</em></sub></small>)<small><sub>3</sub></small>, uncovering a defect-governed evolution of ion migration across different Br compositions. Under dark conditions, ion migration is revealed to be dominated by the specific characteristics of halide interstitial defects, whereas illumination triggers FA-cation migration that strongly correlates with the deep-level defect density. Despite exhibiting comparable halide-migration barriers, high-Br compositions undergo a two-state phase segregation process, comprising an initial thermodynamically driven halide separation followed by a kinetically accelerated regime facilitated by a substantial reduction in the halide migration barrier. These findings provide essential insights for stabilizing wide-bandgap perovskites in high-efficiency tandem photovoltaics.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"14 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao Tian, Shaowei Liu, Fengke Sun, Xiaotao Liu, Chuanli Qin, Zhanjun Zhu, Chuanjiang Qin, Xin Guo, Can Li
Enhancing light emission of organic-inorganic hybrid perovskites is significant for various optoelectric applications. For that purpose, phosphine oxide-based compounds have been widely employed to suppress non-radiative recombination, ascribed to their strong passivation ability to defective sites. Herein, we report that besides passivating defects, phosphine oxide derivatives can induce the surface reconstruction of the perovskite film, forming well-defined nanocrystals during the spincoating process. This in situ nanocrystallization is achieved based on the strong interaction between -P=O groups and perovskites, which leads to partial dissolution of perovskite grains then rapid recrystallization to generate nanocrystalline structures. The nanocrystallized perovskite films exhibit considerably improved photoluminescence owing to the spatial carrier confinement effect, as well as increased electroluminescence performances. The resultant perovskite light-emitting diodes show pure red light with the brightness over three times higher than that of the control devices (from 890 to 2961 cd m -2 ). This work reveals an unaware function of phosphine oxide derivatives in addition to the defect passivation, providing an effective in situ nanocrystallization strategy to boost the light emission of the perovskite film.
增强有机-无机杂化钙钛矿的发光性能对各种光电应用具有重要意义。为此，基于氧化膦的化合物已被广泛用于抑制非辐射重组，归因于它们对缺陷位点的强钝化能力。本文报道，除了钝化缺陷外，氧化膦衍生物还可以诱导钙钛矿膜的表面重建，在旋转涂层过程中形成明确的纳米晶体。这种原位纳米化是基于-P=O基团与钙钛矿之间的强相互作用实现的，这种相互作用导致钙钛矿颗粒部分溶解，然后快速再结晶生成纳米晶结构。由于空间载流子约束效应，纳米晶钙钛矿薄膜的光致发光性能得到了显著改善，电致发光性能也得到了提高。所得的钙钛矿发光二极管显示出纯红光，其亮度比控制器件（从890到2961 cd m -2）高出三倍以上。这项工作揭示了氧化膦衍生物除了缺陷钝化之外的未知功能，为提高钙钛矿薄膜的发光能力提供了一种有效的原位纳米化策略。
{"title":"In situ nanocrystallization on the perovskite film surface for enhanced light emission","authors":"Hao Tian, Shaowei Liu, Fengke Sun, Xiaotao Liu, Chuanli Qin, Zhanjun Zhu, Chuanjiang Qin, Xin Guo, Can Li","doi":"10.1039/d5ta10064j","DOIUrl":"https://doi.org/10.1039/d5ta10064j","url":null,"abstract":"Enhancing light emission of organic-inorganic hybrid perovskites is significant for various optoelectric applications. For that purpose, phosphine oxide-based compounds have been widely employed to suppress non-radiative recombination, ascribed to their strong passivation ability to defective sites. Herein, we report that besides passivating defects, phosphine oxide derivatives can induce the surface reconstruction of the perovskite film, forming well-defined nanocrystals during the spincoating process. This in situ nanocrystallization is achieved based on the strong interaction between -P=O groups and perovskites, which leads to partial dissolution of perovskite grains then rapid recrystallization to generate nanocrystalline structures. The nanocrystallized perovskite films exhibit considerably improved photoluminescence owing to the spatial carrier confinement effect, as well as increased electroluminescence performances. The resultant perovskite light-emitting diodes show pure red light with the brightness over three times higher than that of the control devices (from 890 to 2961 cd m -2 ). This work reveals an unaware function of phosphine oxide derivatives in addition to the defect passivation, providing an effective in situ nanocrystallization strategy to boost the light emission of the perovskite film.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"15 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The electrochemical nitrate reduction reaction (eNO3RR) offers a sustainable strategy for ammonia (NH3) synthesis while simultaneously addressing nitrate pollution. However, its reaction kinetics and selectivity remain constrained, especially on Cu-based electrocatalysts, owing to the premature desorption of the nitrite intermediate (*NO2), which undermines both the NH3 production rate and Faradaic efficiency (FE). In this work, a CuO/Cu2O/CeO2 heterostructure is fabricated on nickel foam via in-situ growth and subsequent calcination. By precisely tuning the calcination temperature, the Cu 2+ /Cu + ratio is effectively modulated. The incorporation of CeO2 induces abundant oxygen vacancies and Lewis acid sites, which cooperatively stabilize Cu δ+ (1<δ<2)
{"title":"Engineering a dual-site CuO/Cu 2 O/CeO 2 heterostructure: synergistic Cu + /Cu 2+ and CeO 2 modulation for tandem ammonia electrosynthesis from nitrate","authors":"Junhua Li, Jun-Ling Song, Wen-Biao Wang, Mei-Qing Cai, Xi-Min Zhang, Hui Qian, Xiaohui XU, Xinjie Tian, Youbing Huang","doi":"10.1039/d5ta09660j","DOIUrl":"https://doi.org/10.1039/d5ta09660j","url":null,"abstract":"The electrochemical nitrate reduction reaction (eNO3RR) offers a sustainable strategy for ammonia (NH3) synthesis while simultaneously addressing nitrate pollution. However, its reaction kinetics and selectivity remain constrained, especially on Cu-based electrocatalysts, owing to the premature desorption of the nitrite intermediate (*NO2), which undermines both the NH3 production rate and Faradaic efficiency (FE). In this work, a CuO/Cu2O/CeO2 heterostructure is fabricated on nickel foam via in-situ growth and subsequent calcination. By precisely tuning the calcination temperature, the Cu 2+ /Cu + ratio is effectively modulated. The incorporation of CeO2 induces abundant oxygen vacancies and Lewis acid sites, which cooperatively stabilize Cu δ+ (1<δ<2)","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"17 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengran Qin, Xiangjie Chen, Xiefei Song, Jifan Wan, Yao He, Kai Xiong
The practical efficiency of Z-scheme photocatalytic heterostructures is often limited by poorly understood interfacial carrier dynamics. While first-principles calculations predict promising static properties for many systems, the critical role of non-adiabatic dynamics remains largely unexplored. Here, we combine non-adiabatic molecular dynamics (NAMD) with first-principles calculations to reveal the ultrafast carrier dynamics in a MoSi2P4/WTe2 heterostructure. Static calculations confirm its direct Z-scheme band alignment and a high strain-tunable corrected solar-to-hydrogen efficiency up to 17.69%, positioning it as a competitive candidate among existing MoSi2P4-based heterostructures. However, NAMD simulations reveal a potential bottleneck for the ideal Z-scheme pathway: the interlayer electron–hole recombination (9.78 ps) is slower than both electron transfer (0.94 ps) and hole transfer (3.48 ps). We demonstrate that these processes are governed by nonadiabatic coupling induced by specific atomic vibrations, rather than static electronic coupling. This mechanistic insight highlights that robust static properties alone are insufficient to guarantee high photocatalytic performance, and that the often-overlooked carrier dynamics can be a decisive factor. This work provides a critical assessment of the MoSi2P4/WTe2 system and underscores the necessity of integrating time-domain investigations for a holistic understanding of photocatalytic heterostructures.
z -方案光催化异质结构的实际效率往往受到对界面载流子动力学了解不足的限制。虽然第一性原理计算预测了许多系统有希望的静态特性，但非绝热动力学的关键作用在很大程度上仍未得到探索。本文将非绝热分子动力学（NAMD）与第一性原理计算相结合，揭示了MoSi2P4/WTe2异质结构中的超快载流子动力学。静态计算证实其直接的Z-scheme波段对准和高应变可调的修正太阳能-氢效率高达17.69%，使其成为现有mosi2p4基异质结构的竞争候选人。然而，NAMD模拟揭示了理想Z-scheme路径的潜在瓶颈：层间电子-空穴复合（9.78 ps）比电子转移（0.94 ps）和空穴转移（3.48 ps）都慢。我们证明了这些过程是由特定原子振动引起的非绝热耦合控制的，而不是静态电子耦合。这种机制的见解强调，仅靠强大的静态特性不足以保证高的光催化性能，而经常被忽视的载流子动力学可能是一个决定性因素。这项工作提供了对MoSi2P4/WTe2体系的关键评估，并强调了整合时域研究以全面理解光催化异质结构的必要性。
{"title":"Static promise versus dynamic reality in a Z-scheme photocatalyst: nonadiabatic dynamics reveal a charge-separation bottleneck in MoSi2P4/WTe2","authors":"Mengran Qin, Xiangjie Chen, Xiefei Song, Jifan Wan, Yao He, Kai Xiong","doi":"10.1039/d5ta09798c","DOIUrl":"https://doi.org/10.1039/d5ta09798c","url":null,"abstract":"The practical efficiency of <em>Z</em>-scheme photocatalytic heterostructures is often limited by poorly understood interfacial carrier dynamics. While first-principles calculations predict promising static properties for many systems, the critical role of non-adiabatic dynamics remains largely unexplored. Here, we combine non-adiabatic molecular dynamics (NAMD) with first-principles calculations to reveal the ultrafast carrier dynamics in a MoSi<small><sub>2</sub></small>P<small><sub>4</sub></small>/WTe<small><sub>2</sub></small> heterostructure. Static calculations confirm its direct <em>Z</em>-scheme band alignment and a high strain-tunable corrected solar-to-hydrogen efficiency up to 17.69%, positioning it as a competitive candidate among existing MoSi<small><sub>2</sub></small>P<small><sub>4</sub></small>-based heterostructures. However, NAMD simulations reveal a potential bottleneck for the ideal <em>Z</em>-scheme pathway: the interlayer electron–hole recombination (9.78 ps) is slower than both electron transfer (0.94 ps) and hole transfer (3.48 ps). We demonstrate that these processes are governed by nonadiabatic coupling induced by specific atomic vibrations, rather than static electronic coupling. This mechanistic insight highlights that robust static properties alone are insufficient to guarantee high photocatalytic performance, and that the often-overlooked carrier dynamics can be a decisive factor. This work provides a critical assessment of the MoSi<small><sub>2</sub></small>P<small><sub>4</sub></small>/WTe<small><sub>2</sub></small> system and underscores the necessity of integrating time-domain investigations for a holistic understanding of photocatalytic heterostructures.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"17 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joonhyeok Park, Hyunjung Park, Seungmin Han, Seungwoo Lee, Jiseok Kwon, Jeongheon Kim, Jun Lim, Ungyu Paik, Taeseup Song
All solid-state batteries (ASSBs) employing sulfide-based electrolytes have attracted great attention as emerging energy storage systems due to high safety, high energy density, broad operating temperatures, etc. However, the introduction of sulfide-based solid electrolytes causes interfacial side-reactions with cathode/anode materials, resulting in electrochemical degradation. Here, we report a new intercalation-type Cu1.8S cathode material with a high capacity and interfacial compatibility for ASSBs. Compared to metal sulfides (MxS), copper sulfides only have metal-rich phases (x ≥ 1.6) due to the unique oxidation state of +1, enabling no weak S–S bonds, all strong Cu–S bonds, and a structural rigidness upon intercalation of foreign atoms. As a starting material, spherical microparticles assembled from CuS nanocrystals are prepared by a solvothermal method. After calcination at 300 °C, the CuS granules are transformed to porous Cu1.8S microspheres with a particle size of 1–3 µm and a surface area of 1.4 m2 g−1. A Cu1.8S-based cathode shows a charge/discharge capacity of 274 mAh g−1, a capacity retention of 80% over 100 cycles, and a high-rate capability of ∼190 mAh g−1 at 1C-rate in a potential window of 0.5–2.5 V vs. Li/Li+, leading to 1.5 times higher energy density than that of the conventional LiCoO2 cathode. In addition, it shows a suppressed side reaction and electrochemical compatibility with the sulfide-based electrolyte. The achievements open a new avenue for the potential use of copper sulfides as cathode materials for ASSBs.
采用硫化物基电解质的全固态电池（assb）由于具有高安全性、高能量密度、工作温度宽等优点，作为一种新兴的储能系统受到了广泛的关注。然而，硫化物基固体电解质的引入会引起与阴极/阳极材料的界面副反应，导致电化学降解。本文报道了一种具有高容量和界面相容性的新型插层型Cu1.8S阴极材料。与金属硫化物（MxS）相比，铜硫化物由于其独特的+1氧化态，只有富金属相（x≥1.6），没有弱S-S键，所有强Cu-S键，并且在外来原子插入时具有结构刚性。以cu纳米晶为原料，采用溶剂热法制备球形微粒子。在300℃下煅烧后，cu颗粒转化为多孔Cu1.8S微球，粒径为1 ~ 3µm，表面积为1.4 m2 g−1。cu1.8基阴极的充放电容量为274 mAh g−1，在100次循环中容量保持率为80%，在0.5-2.5 V vs. Li/Li+的电位窗口中，在1c倍率下的高倍率容量为~ 190 mAh g−1，导致能量密度比传统LiCoO2阴极高1.5倍。此外，它还表现出抑制副反应和与硫化物基电解质的电化学相容性。这一成果为硫化铜作为assb阴极材料的潜在应用开辟了新的途径。
{"title":"High capacity metal-rich copper sulfide as an intercalation-type cathode material for all solid-state batteries","authors":"Joonhyeok Park, Hyunjung Park, Seungmin Han, Seungwoo Lee, Jiseok Kwon, Jeongheon Kim, Jun Lim, Ungyu Paik, Taeseup Song","doi":"10.1039/d5ta10602h","DOIUrl":"https://doi.org/10.1039/d5ta10602h","url":null,"abstract":"All solid-state batteries (ASSBs) employing sulfide-based electrolytes have attracted great attention as emerging energy storage systems due to high safety, high energy density, broad operating temperatures, <em>etc</em>. However, the introduction of sulfide-based solid electrolytes causes interfacial side-reactions with cathode/anode materials, resulting in electrochemical degradation. Here, we report a new intercalation-type Cu<small><sub>1.8</sub></small>S cathode material with a high capacity and interfacial compatibility for ASSBs. Compared to metal sulfides (M<small><sub><em>x</em></sub></small>S), copper sulfides only have metal-rich phases (<em>x</em> ≥ 1.6) due to the unique oxidation state of +1, enabling no weak S–S bonds, all strong Cu–S bonds, and a structural rigidness upon intercalation of foreign atoms. As a starting material, spherical microparticles assembled from CuS nanocrystals are prepared by a solvothermal method. After calcination at 300 °C, the CuS granules are transformed to porous Cu<small><sub>1.8</sub></small>S microspheres with a particle size of 1–3 µm and a surface area of 1.4 m<small><sup>2</sup></small> g<small><sup>−1</sup></small>. A Cu<small><sub>1.8</sub></small>S-based cathode shows a charge/discharge capacity of 274 mAh g<small><sup>−1</sup></small>, a capacity retention of 80% over 100 cycles, and a high-rate capability of ∼190 mAh g<small><sup>−1</sup></small> at 1C-rate in a potential window of 0.5–2.5 V <em>vs.</em> Li/Li<small><sup>+</sup></small>, leading to 1.5 times higher energy density than that of the conventional LiCoO<small><sub>2</sub></small> cathode. In addition, it shows a suppressed side reaction and electrochemical compatibility with the sulfide-based electrolyte. The achievements open a new avenue for the potential use of copper sulfides as cathode materials for ASSBs.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"33 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dayeon Lee, Neul Ha, Jaemin Park, Jisu Jung, Jaewook Lee, Ji Hoon Kim, Sang Uck Lee, Dong-Won Kang, Kaiying Wang, Wooseok Yang
AgBiS 2 has emerged as a highly promising light-absorbing material for solar energy conversion owing to its direct band gap, strong visible-light absorption, and compatibility with scalable solution-based processing. A particularly intriguing characteristic of AgBiS 2 is that its optical absorption coefficient can be markedly enhanced through cation-disorder engineering.Previous studies have demonstrated that solution chemistry can induce cation disorder in AgBiS 2 ; however, it simultaneously governs crystal growth and morphology, including the formation of one-dimensional nanostructures. Despite its importance, the interplay between cation disorder and morphology control has remained poorly understood. Here, we systematically investigate the chemical interactions among thiourea (TU), serving as both a sulfur (S) source and coordinating ligand, metal cations (Ag + and Bi 3+ ), and dimethyl sulfoxide (DMSO) as the solvent. Density-functional-theory calculations combined with spectroscopic and structural analyses consistently reveal that both TU and DMSO bind more strongly to Bi 3+ than to Ag⁺. Notably, the comparable binding energies of the TU-Bi and DMSO-Bi complexes impose a thermodynamic constraint on cation disorder. Consequently, increasing the TU concentration suppresses cation disorder, while instead promoting anisotropic crystal growth, leading to the formation of one-dimensional AgBiS 2 nanostructures through specific TU-metal coordination. Furthermore, AgBiS 2 thin-film photocathodes with controlled nanostructures were fabricated and evaluated for photoelectrochemical (PEC) water splitting, demonstrating how the chemically driven trade-off between cation disorder and morphology directly influences PEC performance.
{"title":"Precursor Chemistry Governing Morphology and Cation Disorder in AgBiS 2 Solar Absorber for Photoelectrochemical Water Splitting","authors":"Dayeon Lee, Neul Ha, Jaemin Park, Jisu Jung, Jaewook Lee, Ji Hoon Kim, Sang Uck Lee, Dong-Won Kang, Kaiying Wang, Wooseok Yang","doi":"10.1039/d6ta01212d","DOIUrl":"https://doi.org/10.1039/d6ta01212d","url":null,"abstract":"AgBiS 2 has emerged as a highly promising light-absorbing material for solar energy conversion owing to its direct band gap, strong visible-light absorption, and compatibility with scalable solution-based processing. A particularly intriguing characteristic of AgBiS 2 is that its optical absorption coefficient can be markedly enhanced through cation-disorder engineering.Previous studies have demonstrated that solution chemistry can induce cation disorder in AgBiS 2 ; however, it simultaneously governs crystal growth and morphology, including the formation of one-dimensional nanostructures. Despite its importance, the interplay between cation disorder and morphology control has remained poorly understood. Here, we systematically investigate the chemical interactions among thiourea (TU), serving as both a sulfur (S) source and coordinating ligand, metal cations (Ag + and Bi 3+ ), and dimethyl sulfoxide (DMSO) as the solvent. Density-functional-theory calculations combined with spectroscopic and structural analyses consistently reveal that both TU and DMSO bind more strongly to Bi 3+ than to Ag⁺. Notably, the comparable binding energies of the TU-Bi and DMSO-Bi complexes impose a thermodynamic constraint on cation disorder. Consequently, increasing the TU concentration suppresses cation disorder, while instead promoting anisotropic crystal growth, leading to the formation of one-dimensional AgBiS 2 nanostructures through specific TU-metal coordination. Furthermore, AgBiS 2 thin-film photocathodes with controlled nanostructures were fabricated and evaluated for photoelectrochemical (PEC) water splitting, demonstrating how the chemically driven trade-off between cation disorder and morphology directly influences PEC performance.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"13 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ho Rim Kim, Du Yeol Jo, Hong Geun Oh, Jeong Ho Na, Hyun Jin Kim, Seong-Yong Jeong, Seung-Keun Park
The Pomegranate-like carbon microclusters (P-CMs), constructed from densely assembled hollow carbon spheres, provide interconnected internal voids that can accommodate Li and mitigate macroscopic volume changes. However, despite this advantageous architecture, Li deposition in P-CMs often remains surface-biased owing to insufficient interfacial lithiophilicity and non-uniform solid-electrolyte interphase formation. These interfacial limitations lead to localized Li nucleation, gradual Li accumulation on the outer surface, and eventual dendritic growth under prolonged cycling conditions.In this study, we applied a conformal polydopamine (PDA) nanoskin coating on the P-CM (the resulting sample is denoted as P-CM@PDA) to regulate its Li nucleation behavior and stabilize the interfacial chemistry. The PDA-derived catechol/amine functional groups provide abundant lithiophilic sites that lower the nucleation barrier and homogenize the Li + flux, while the hierarchical P-CM framework facilitates inward Li infusion through continuous ionic pathways. Consequently, P-CM@PDA achieves highly reversible Li plating/stripping, with a stable Coulombic efficiency of ~97% for 150 cycles at 3.0 mA h cm -2 , and maintains long-term symmetric cell cycling for more than 450 h at 2.0 mA cm -2 and 1.0 mA h cm -2 . When paired with a LiFePO4 cathode, the full cell delivers a high reversible discharge capacity of 141.8 mA h g -1 with > 99% capacity retention over 350 cycles and superior rate capability up to 10C rate. This study demonstrates that interfacial lithiophilicity enhancement, rather than structural redesign alone, is the key to enabling dense, dendrite-free Li storage in hierarchical carbon hosts, providing a promising pathway to high-energy lithium metal batteries.
石榴状碳微团簇（P-CMs）由密集组装的空心碳球构成，提供了相互连接的内部空隙，可以容纳锂并减轻宏观体积变化。然而，尽管有这种有利的结构，由于界面亲石性不足和不均匀的固体-电解质间相形成，P-CMs中的Li沉积经常保持表面偏置。在长时间循环条件下，这些界面限制导致局部锂成核，逐渐在外表面积累，最终形成枝晶。在本研究中，我们在P-CM（所得样品表示为P-CM@PDA）上应用保形聚多巴胺（PDA）纳米皮涂层来调节其Li成核行为并稳定界面化学。pda衍生的儿茶酚/胺官能团提供了丰富的亲石位点，降低了成核屏障并使Li +通量均匀化，而分层的P-CM框架则通过连续的离子途径促进Li向内灌注。因此，P-CM@PDA实现了高度可逆的锂电镀/剥离，在3.0 mA h cm -2下循环150次，库仑效率稳定在97%左右，并在2.0 mA cm -2和1.0 mA h cm -2下保持了超过450小时的长期对称电池循环。当与LiFePO4阴极配对时，整个电池提供141.8 mA h g -1的高可逆放电容量，在350次循环中保持99%的容量，并具有高达10C的卓越倍率能力。这项研究表明，界面亲石性的增强，而不是单纯的结构重新设计，是在分层碳宿主中实现致密、无枝晶锂存储的关键，为高能锂金属电池提供了一条有希望的途径。
{"title":"Lithiophilic Nanoskin-Enabled Dendrite-Free Li Deposition in Pomegranate-like Carbon Microclusters","authors":"Ho Rim Kim, Du Yeol Jo, Hong Geun Oh, Jeong Ho Na, Hyun Jin Kim, Seong-Yong Jeong, Seung-Keun Park","doi":"10.1039/d5ta09478j","DOIUrl":"https://doi.org/10.1039/d5ta09478j","url":null,"abstract":"The Pomegranate-like carbon microclusters (P-CMs), constructed from densely assembled hollow carbon spheres, provide interconnected internal voids that can accommodate Li and mitigate macroscopic volume changes. However, despite this advantageous architecture, Li deposition in P-CMs often remains surface-biased owing to insufficient interfacial lithiophilicity and non-uniform solid-electrolyte interphase formation. These interfacial limitations lead to localized Li nucleation, gradual Li accumulation on the outer surface, and eventual dendritic growth under prolonged cycling conditions.In this study, we applied a conformal polydopamine (PDA) nanoskin coating on the P-CM (the resulting sample is denoted as P-CM@PDA) to regulate its Li nucleation behavior and stabilize the interfacial chemistry. The PDA-derived catechol/amine functional groups provide abundant lithiophilic sites that lower the nucleation barrier and homogenize the Li + flux, while the hierarchical P-CM framework facilitates inward Li infusion through continuous ionic pathways. Consequently, P-CM@PDA achieves highly reversible Li plating/stripping, with a stable Coulombic efficiency of ~97% for 150 cycles at 3.0 mA h cm -2 , and maintains long-term symmetric cell cycling for more than 450 h at 2.0 mA cm -2 and 1.0 mA h cm -2 . When paired with a LiFePO4 cathode, the full cell delivers a high reversible discharge capacity of 141.8 mA h g -1 with > 99% capacity retention over 350 cycles and superior rate capability up to 10C rate. This study demonstrates that interfacial lithiophilicity enhancement, rather than structural redesign alone, is the key to enabling dense, dendrite-free Li storage in hierarchical carbon hosts, providing a promising pathway to high-energy lithium metal batteries.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"29 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While plastic offers exceptional properties and economic efficiencies, its indiscriminate disposal presents a significant threat to humans and the environment. Recycling plays a significant role in shifting from a linear to a circular economy. Among various methods, chemical depolymerization of plastic wastes enables the recovery of high-value monomers, offering an effective solution to resource recovery and environmental remediation. Although polylactic acid (PLA) is a biodegradable polymer, its extensive use in various applications has resulted in significant waste accumulation. Therefore, developing efficient chemical depolymerization strategies is essential to reduce environmental pollution caused by PLA and promote its circular economy. In this work, Ni-TiO2 catalyst was employed for the glycolysis of PLA, yielding 2-hydroxyethyl lactate as a selective depolymerization product. The reaction was performed under relatively mild conditions, and the parameters were optimized to obtain good selectivity and product yield. The best yield (98%) was obtained at 190 °C for a reaction time of 8 h. A gram-scale-experiment was also performed to demonstrate the large-scale implementation of this reaction. Additionally, green metric parameters were analyzed to assess the sustainability of the designed reaction protocol. The Ni-TiO2 catalyst also demonstrated excellent recyclability, maintaining consistent product yield over five consecutive cycles without any loss in activity. This study presents a sustainable and environmentally benign approach for the catalyst-assisted chemical depolymerization of PLA to a selective monomer in high yields.
{"title":"Bifunctional Ni-TiO2 catalyst for the efficient glycolysis of polylactic acid: a selective route to obtain 2-hydroxyethyl lactate","authors":"Kamlesh Kumari, Shadab Khan, Venkata Krishnan","doi":"10.1039/d5ta10188c","DOIUrl":"https://doi.org/10.1039/d5ta10188c","url":null,"abstract":"While plastic offers exceptional properties and economic efficiencies, its indiscriminate disposal presents a significant threat to humans and the environment. Recycling plays a significant role in shifting from a linear to a circular economy. Among various methods, chemical depolymerization of plastic wastes enables the recovery of high-value monomers, offering an effective solution to resource recovery and environmental remediation. Although polylactic acid (PLA) is a biodegradable polymer, its extensive use in various applications has resulted in significant waste accumulation. Therefore, developing efficient chemical depolymerization strategies is essential to reduce environmental pollution caused by PLA and promote its circular economy. In this work, Ni-TiO<small><sub>2</sub></small> catalyst was employed for the glycolysis of PLA, yielding 2-hydroxyethyl lactate as a selective depolymerization product. The reaction was performed under relatively mild conditions, and the parameters were optimized to obtain good selectivity and product yield. The best yield (98%) was obtained at 190 °C for a reaction time of 8 h. A gram-scale-experiment was also performed to demonstrate the large-scale implementation of this reaction. Additionally, green metric parameters were analyzed to assess the sustainability of the designed reaction protocol. The Ni-TiO<small><sub>2</sub></small> catalyst also demonstrated excellent recyclability, maintaining consistent product yield over five consecutive cycles without any loss in activity. This study presents a sustainable and environmentally benign approach for the catalyst-assisted chemical depolymerization of PLA to a selective monomer in high yields.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"59 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the microstructure of low calcium aluminosilicate hydrate (C-A-S-H) and calcium containing sodium aluminosilicate hydrate (N(-C)-A-S-H) is essential for the performance prediction and therefore manufacturing of geopolymers, or more broadly, chemically activated aluminosilicate cements. This study aims to reveal their atomic ordering and molecular structure using synthetic C-A-S-H/N(-C)-A-S-H gels at low Ca/Si (0-1.0) and Si/Al (1-2) ratios. By high energy XRD with pair distribution function (PDF) analysis, TEM, and 29Si/27Al NMR analysis, it discovers that Ca concentration is a more governing factor than Al to the overall Si/Al evolution of gels. The formation of distinct Q1 and Q2 structural units is at the conditions of Si/Al > 1.75 and Ca/Si ≥ ~0.2-0.5. Ca and Al exhibit synergistic/antagonistic effect on Si tetrahedral units: Al increases Q4 (enhancing polymerization), while Ca promotes Q2 (improving ordering) but reduces Q3 (decreasing connectivity). An estimation calculation formula linking the proportion of Q4 sites to Si/Al and measured Ca/Si ratios of products is established to simplify the determination of C-A-S-H and N(-C)-A-S-H gel proportions in alkali-activated systems (including low-Ca hybrid alkaline cement). The new insights and discovery of C-A-S-H and N-A-S-(H) gel microstructure enables future work of better understanding the relationship between phase composition and geopolymer performances. The findings elucidate the interactions and mechanisms of elemental composition governing gel evolution, with implication for geopolymer manufacturing and application.
了解低钙水合铝硅酸钠（C-A-S-H）和含钙水合铝硅酸钠（N(c) a - s - h）的微观结构对于性能预测和地聚合物的制造至关重要，或者更广泛地说，化学活化的铝硅酸水泥。本研究旨在通过合成低Ca/Si（0-1.0）和Si/Al（1-2）比的C-A-S-H/N(-C) a - s - h凝胶揭示它们的原子有序和分子结构。通过对分布函数（PDF）分析、透射电镜（TEM）和29Si/27Al核磁共振（NMR）分析，发现Ca浓度对凝胶整体Si/Al演化的控制作用大于Al。在Si/Al >； 1.75和Ca/Si≥~0.2-0.5的条件下，形成了不同的Q1和Q2结构单元。Ca和Al对Si四面体单元表现出协同/拮抗作用：Al增加Q4（增强聚合），而Ca促进Q2（改善有序），但降低Q3（降低连接）。为了简化碱活化体系（包括低钙混合碱性水泥）中C-A-S-H和N(c) a - s - h凝胶比例的测定，建立了一个将Q4位点与Si/Al的比例和测定产物的Ca/Si比联系起来的估算计算公式。C-A-S-H和N-A-S-(H)凝胶微观结构的新见解和发现，使未来的工作能够更好地理解相组成与地聚合物性能之间的关系。这些发现阐明了元素组成控制凝胶演化的相互作用和机制，对地聚合物的制造和应用具有指导意义。
{"title":"Intrinsic microstructure of C-A-S-H and N(-C)-A-S-H gels at low Ca/Si and Si/Al ratios","authors":"Yulin Deng, Zuhua Zhang","doi":"10.1039/d5ta09930g","DOIUrl":"https://doi.org/10.1039/d5ta09930g","url":null,"abstract":"Understanding the microstructure of low calcium aluminosilicate hydrate (C-A-S-H) and calcium containing sodium aluminosilicate hydrate (N(-C)-A-S-H) is essential for the performance prediction and therefore manufacturing of geopolymers, or more broadly, chemically activated aluminosilicate cements. This study aims to reveal their atomic ordering and molecular structure using synthetic C-A-S-H/N(-C)-A-S-H gels at low Ca/Si (0-1.0) and Si/Al (1-2) ratios. By high energy XRD with pair distribution function (PDF) analysis, TEM, and 29Si/27Al NMR analysis, it discovers that Ca concentration is a more governing factor than Al to the overall Si/Al evolution of gels. The formation of distinct Q1 and Q2 structural units is at the conditions of Si/Al > 1.75 and Ca/Si ≥ ~0.2-0.5. Ca and Al exhibit synergistic/antagonistic effect on Si tetrahedral units: Al increases Q4 (enhancing polymerization), while Ca promotes Q2 (improving ordering) but reduces Q3 (decreasing connectivity). An estimation calculation formula linking the proportion of Q4 sites to Si/Al and measured Ca/Si ratios of products is established to simplify the determination of C-A-S-H and N(-C)-A-S-H gel proportions in alkali-activated systems (including low-Ca hybrid alkaline cement). The new insights and discovery of C-A-S-H and N-A-S-(H) gel microstructure enables future work of better understanding the relationship between phase composition and geopolymer performances. The findings elucidate the interactions and mechanisms of elemental composition governing gel evolution, with implication for geopolymer manufacturing and application.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"1 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenlong Yang, Zhenghui Ma, Guoli Fan, Xiaoyan Pu, Feng Li
Photocatalytic CO2 reduction to produce high value-added hydrocarbons has attracted significant attention, yet its overall efficiency remains unsatisfactory. In this work, a micro-liquid film reactor featuring enhanced mixing efficiency was utilized to realize the doping of single Fe atoms into the lattice of TiO2, enabling the generation of abundant atomically dispersed Feδ+ -Ov-Ti structures (Ov: oxygen vacancy). The results showed that compared to pristine TiO2, the optimized Fe-TiO2 photocatalyst bearing a 4 wt.% Fe content exhibited 15.2 times higher activity, with a significant shift in the predominant product from CO to CH4, as well as an impressively high CH4 formation rate of 29.2 μmol•g-1•h-1 , surpassing those over most of the state-of-the-art TiO2-based photocatalysts previously reported. It was revealed that the incorporation of single-atom Fe could reduce the bandgap of TiO2 matrix and surface atomically dispersed Feδ+ -Ov structures could improve the separation efficiency of photogenerated charge carriers and facilitated the adsorption and activation of CO2 and the formation and stabilization of key *CO reaction intermediate, thereby accelerating photocatalytic CO2 reduction to produce CH4. The present work affords a simple and efficient strategy for designing single-atom Fe-regulated TiO2-based photocatalysts for a synergistic enhancement of CO2 photoreduction activity and CH4 selectivity.
{"title":"Engineering atomically dispersed Fe sites into TiO2 for largely enhanced photocatalytic CO2 reduction to CH4","authors":"Wenlong Yang, Zhenghui Ma, Guoli Fan, Xiaoyan Pu, Feng Li","doi":"10.1039/d6ta01196a","DOIUrl":"https://doi.org/10.1039/d6ta01196a","url":null,"abstract":"Photocatalytic CO2 reduction to produce high value-added hydrocarbons has attracted significant attention, yet its overall efficiency remains unsatisfactory. In this work, a micro-liquid film reactor featuring enhanced mixing efficiency was utilized to realize the doping of single Fe atoms into the lattice of TiO2, enabling the generation of abundant atomically dispersed Feδ+ -Ov-Ti structures (Ov: oxygen vacancy). The results showed that compared to pristine TiO2, the optimized Fe-TiO2 photocatalyst bearing a 4 wt.% Fe content exhibited 15.2 times higher activity, with a significant shift in the predominant product from CO to CH4, as well as an impressively high CH4 formation rate of 29.2 μmol•g-1•h-1 , surpassing those over most of the state-of-the-art TiO2-based photocatalysts previously reported. It was revealed that the incorporation of single-atom Fe could reduce the bandgap of TiO2 matrix and surface atomically dispersed Feδ+ -Ov structures could improve the separation efficiency of photogenerated charge carriers and facilitated the adsorption and activation of CO2 and the formation and stabilization of key *CO reaction intermediate, thereby accelerating photocatalytic CO2 reduction to produce CH4. The present work affords a simple and efficient strategy for designing single-atom Fe-regulated TiO2-based photocatalysts for a synergistic enhancement of CO2 photoreduction activity and CH4 selectivity.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"7 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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