EcoMat最新文献

The partial Pb²⁺ substitution with Cu⁺ ions has been thoroughly applied as an approach to produce new absorber materials with enhanced light and radiation hardness required for potential aerospace applications of perovskite solar cells. X-ray photoelectron spectroscopy revealed that Cu⁺ ions are partially integrated into the crystal lattice of MAPbI₃ on the surface of perovskite grains and induce p-doping effect, which is crucial for a range of applications. Importantly, the presence of Cu⁺ enhances photostability of perovskite films and blocks the formation of metallic lead as a photolysis product. Furthermore, we have carried out one of the first studies on the radiation hardness of complex lead halides exposed to two different stressors: γ-rays and 8.5 MeV electron beams. The obtained results demonstrate that Cu⁺ doping alters completely the radiation-induced degradation pathways of the double cation perovskite. Indeed, while Cs_0.12FA_0.88PbI₃ degrades mostly with segregation of δ-phase of FAPbI₃ forming a Cs-rich perovskite phase, the Cs_0.12FA_0.88Pb_0.99Cu_0.01I_2.99 films tend to expel δ-CsPbI₃ and produce FA-rich perovskite phase, which shows impressive tolerance to both γ-rays and high energy electrons. The beneficial effect of copper ion incorporation on the stability of lead halide perovskite solar cells under light soaking and γ-ray irradiation conditions has been shown. The discovered possibility of controlling the electronic properties and major materials degradation pathways through minor modification of their chemical composition (e.g., replacing 1% of Pb²⁺ with Cu⁺) opens up tremendous opportunities for engineering new perovskite absorber compositions with significantly improved properties for both terrestrial and aerospace applications.

The complex molecular structures of electron donor (D)–acceptor (A) polymers provide a wealth of useful hints for producing high power conversion efficiency (PCE) as hole transport materials (HTMs) in perovskite solar cells (PVSCs). Given the recent improvements in PCE, various features are focused on altering the functionalities of HTMs. In this study, a pyrazine-based acceptor is fused with two known donors benzodithiophene (BDT) and dithienobenzodithiophene (DTBDT) to synthesize two new D–A type polymers (NBD-Pyz and NDT-Pyz) to employ them as dopant-free HTM in PVSCs. The insertion of pyrazine moiety downshifted the energy levels and enhanced coplanarity for both the HTMs. NBD-Pyz can significantly lower the trap density and passivate the perovskite layer. More interestingly, the NBD-Pyz HTM performs better than NDT-Pyz, exhibiting higher hole mobility and better solubility in 2-methyl anisole (2MA) and o-xylene. Moreover, a 2MA/o-xylene cosolvent-processed dopant-free polymeric NBD-Pyz HTM-based device achieved a champion PCE of 22.9%. Unlike NDT-Pyz and Spiro-OMeTAD-based PVSCs, the unencapsulated NBD-Pyz devices were more stable, retaining almost 90% of their initial efficiency after 1000 h. In addition, excellent thermal stability was demonstrated by the resulting PVSCs without encapsulation.

Crosslinked organic semiconductors have opened the way for various fabrication techniques in the field of organic electronics owing to their three-dimensional network structure with high solvent resistivity. However, recent efforts to synthesize cross-linkable semiconducting polymers have been limited by their low molecular weights and yields. In this study, this limitation is overcome by a novel post-polymerization strategy. A reagent with a cross-linkable functional group, (3-mercaptopropyl)trimethoxysilane, is attached to a diketopyrrolopyrrole-based donor–acceptor copolymer (DPPTT) via thioesterification and para-fluoro-thiol reaction, modifying two sites simultaneously. This modification preserves the molecular weight and electrical properties of the original polymers. In addition, the use of click chemistry enables high yield (98%) without any purification. The modified DPPTT demonstrated high resistance to organic solvents (80% retention dipped in 1-chlorobenzene for 1 h). Exploiting this benefit, an ultrathin flexible array of 100 organic field-effect transistors fabricated using conventional photolithography showed high-performance reliability. Thus, this study provides a universal strategy to synthesize versatile polymer semiconductors for practical organic electronics.

The temperature of metal-based facilities rises significantly under high outdoor solar irradiation, leading to serious safety accidents. The application of active cooling technology poses challenges due to its high energy consumption, especially in complex outdoor environments. Passive cooling devices with high solar reflection and thermal emission can continuously cool objects under sunlight. However, the white or silvery passive cooling devices do not meet the need for aesthetics and specific demands. Here, we present a hierarchical metapaint for outdoor facilities that simultaneously achieve vibrant color and passive cooling ability. The top layer selectively absorbs visible wavelengths to display desired colors, while the underlayer boosts the reflection of near-to-short wavelength infrared (NSWIR) light to prevent solar heating. The metapaint-coated metal is resistant to high and low temperatures, acidic and alkaline environments, and simulated seawater. It also has satisfactory anti-fouling properties. When compared to metal coated without commercial paint, the hierarchical passive cooling paint (metapaint) coated metal can cool up to 9.7°C and 17.1°C. The metapaint has excellent passive cooling performance, attributed to its broad-spectrum selective regulation function. Our work offers a simple, inexpensive, and scalable approach to reduce cooling energy usage and promote a low-carbon lifestyle.

Layered double hydroxides (LDHs) are ionic layered compounds characterized by anion-containing intermediate regions within positively charged brucite-like layers. LDHs have shown high electrochemical activity in energy conversion systems such as batteries and fuel cells. In this study, we developed a hierarchically porous nanostructure derived from zeolitic imidazolate framework-67, which was subsequently transformed into an LDH structure with varying Ni concentrations. We precisely controlled the Ni-to-Co ratio within the LDH structure and investigated how different mole fractions of Co and Ni influence catalytic activity and selectivity for the electrochemical urea oxidation reaction (UOR). LDH structures with low Ni content (up to 40%) demonstrated high activity and selectivity for O₂ due to their structural instability and the predominant oxygen evolution reaction (OER) originating from ZIF-67. In contrast, LDHs with high Ni content (over 60%) supressed OER and exhibited enhanced activity for UOR. The resulting hollow structure with an expanded electrochemically active surface in LDHs with high Ni content could improve mass transport and diffusion at the electrode interface, leading to better reaction kinetics and higher current densities. These findings provide a foundational design guideline for metal–organic framework-derived nanostructure in UOR.

A novel approach to enhancing the efficiency and long-term stability of perovskite solar cells (PSCs) is presented through strategic interfacial modification using bespoke graphene quantum dots (GQDs). GQDs with controlled alkylamine chain lengths, such as butylamine (C4), octylamine (C8), and dodecylamine (C12), were customized to have the proper optical and electronic properties toward specific interfaces within the PSCs. The incorporation of C4-GQDs significantly improved the energy level alignment and conductivity of the SnO₂ electron transport layer (ETL), while C12-GQDs effectively reduced trap density on the perovskite surface, leading to enhanced defect passivation. These modifications resulted in a substantial increase in power conversion efficiency of 24.41% in a unit cell and 18.91% in a mini-module, respectively. Notably, the maximum power point tracked perovskite mini-module retained 89% of its initial efficiency during 1000 h of continuous light soaking condition at 25°C under 35% relative humidity. This work highlights the potential of bespoke GQDs to advance both the performance and durability of PSCs, providing a scalable approach for future photovoltaic applications.

Supercapacitors show broad application prospects as promising energy supply units for future integrated or even implantable electronic devices, but their poor degradability and high biotoxicity severely limit their further development. Regarding this, future-oriented supercapacitors with fully degradable behavior and excellent biosafety have been prepared through the wide application of degradable polymers and a rational encapsulation and isolation strategy. The combination of self-supporting pulp fiber/graphene composite electrodes and guar gum gel electrolyte endows the devices with ideal rate performance and long lifetime. The devices demonstrate extremely low cytotoxicity and satisfactory biocompatibility. The implantation caused no significant rejection and did not affect the survival status of the SD rats, suggesting the possibility of powering implantable electronics. Notably, all components of the device (electrodes, electrolyte, substrate, and encapsulation materials) do not contain hazardous or non-degradable materials, allowing for true complete degradability. The preparation strategy and material selection in the study are expected to be generalized to a wide range of energy storage systems, providing some reference and guidance for the harmless disposal of energy storage devices and even microelectronics.

Nickel-Zinc (Ni-Zn) batteries offer an interesting alternative for the expanding electrochemical energy storage industry due to their high-power density, low cost, and environmental friendliness. However, significant reliability challenges such as capacity fading, self-discharge, thermal instability, and electrode degradation detract from their competitiveness in the market, hindering their widespread adoption. This study thoroughly examines the degradation mechanisms and approaches to improve the reliability of Ni-Zn batteries: Starting with their basic chemistry, operating principles, and degradation pathways, strategies for improvement are explored including material modification, electrolyte optimization, cell design approaches, and thermal management techniques. Advanced characterization methods for data collection and reliability assessment are discussed, including electrochemical, structural, spectroscopic, and in situ techniques which are noted for their ability to identify key areas of concern for this cell chemistry. We further consider emerging trends such as novel materials, hybridization with other energy technologies, and the challenges of large-scale implementation, emphasizing the need for standardized reliability testing protocols. Opportunities for the integration of advanced sensing, such as fiber Bragg grating (FBG) sensors for real-time monitoring and anomaly detection, along with machine learning (ML) and prognostics and health management of Ni-Zn batteries are highlighted, as these open the door to future research directions. This comprehensive review should serve as a resource for researchers, engineers, and industry experts aiming to advance and commercialize dependable, high-performing Ni-Zn battery technology for a sustainable energy future.

Pt-based electrocatalysts for glycerol oxidation reaction (GOR) exhibit low durability due to the inactivation of Pt through rapid poisoning under oxidative conditions. Thus, bimetallic PtBi was strategically synthesized using BiOI as a photoactive intermediate for the uniform photoelectrodeposition of Pt. The nanostructured Pt–Bi was electrochemically reduced from a Pt/BiOI medium, and the GOR-activated Pt–Bi electrocatalysts (G–Pt–Bi) were obtained via a subsequent electrochemical activation process. Here, abundant Bi sites in PtBi can prevent Pt poisoning and effectively provide adsorbed OH⁻ for the GOR on Pt sites. Consequently, it allows the operation in low onset potential for GOR with a high mass activity of 13.35 A mg_Pt ⁻¹ at 0.85 V_RHE in alkaline solution. The GOR products obtained using G–Pt–Bi were identified as glycolate and formate by ¹H-nuclear magnetic resonance without the interruption of the hydrogen evolution reaction, and it finally enables the operation of a membrane-free two-electrode system. In situ electrochemical impedance spectroscopy demonstrates that the G–Pt–Bi exhibit superior GOR kinetics and higher resistance to Pt inactivation compared with conventional Pt/C. This study suggests a novel design for a G–Pt–Bi architecture in developing durable and high-mass-activity Pt catalysts for the GOR.

Two-dimensional Ruddlesden-Popper (2D RP) layered metal-halide perovskites have garnered increasing attention due to their favorable optoelectronic properties and enhanced stability in comparison to their three-dimensional counterparts. Nevertheless, precise control over the crystal orientation of 2D RP perovskite films remains challenging, primarily due to the intricacies associated with the solvent evaporation process. In this study, we introduce a novel approach known as reverse-cool annealing (RCA) for the fabrication of 2D RP perovskite films. This method involves a sequential annealing process at high and low temperatures for wet perovskite films. The resulting RCA-based perovskite films show the smallest root-mean-square value of 23.1 nm, indicating a minimal surface roughness and a notably compact and smooth surface morphology. The low defect density in these 2D RP perovskite films with exceptional crystallinity suppresses non-radiative recombination, leading to a minimal non-radiative open-circuit voltage loss of 149 mV. Moreover, the average charge lifetime in these films is extended to 56.3 ns, thanks to their preferential growth along the out-of-plane direction. Consequently, the leading 2D RP perovskite solar cell achieves an impressive power conversion efficiency of 17.8% and an open-circuit voltage of 1.21 V. Additionally, the stability of the 2D RP perovskite solar cell, even without encapsulation, exhibits substantial improvement, retaining 97.4% of its initial efficiency after 1000 hours under a nitrogen environment. The RCA strategy presents a promising avenue for advancing the commercial prospects of 2D RP perovskite solar cells.