Seawater electrolysis for hydrogen production represents a substantial opportunity to curtail production expenditures and exhibits considerable potential for various industrial applications. Platinum-based precious metals exhibit excellent activity for water electrolysis. However, their limited reserves and high costs impede their widespread use on a large scale. Single-atom catalysts, characterized by low loading and high utilization efficiency, represent a viable alternative, and the development of simple synthesis methods can facilitate their practical application. In this work, we report the facile synthesis of a single-atom Pt-loaded NiCoFeSx (Pt@NiCoFeSx) bifunctional catalytic electrode using a simple impregnation method on a nickel foam substrate. The resulting electrode exhibits low overpotentials for both HER (60 mV@10 mA cm−2) and OER (201 mV@10 mA cm−2) in alkaline seawater electrolytes. When incorporated into a seawater electrolyzer, this electrode achieves a direct current energy consumption of only 4.18 kWh/Nm3H2 over a 100 h test period with negligible decay. These findings demonstrate the potential of our approach for industrial-scale seawater electrolysis.
海水电解制氢是减少生产成本的一个重要机会，在各种工业应用中具有相当大的潜力。以铂为基础的贵金属在水电解方面表现出卓越的活性。然而，其有限的储量和高昂的成本阻碍了其大规模的广泛应用。单原子催化剂具有低负载和高利用效率的特点，是一种可行的替代方法，而开发简单的合成方法则可促进其实际应用。在这项工作中，我们报告了在泡沫镍基底上采用简单的浸渍方法轻松合成单原子铂负载镍钴铁氧体（Pt@NiCoFeSx）双功能催化电极的情况。所制备的电极在碱性海水电解质中对 HER（60 mV@10 mA cm-2）和 OER（201 mV@10 mA cm-2）均表现出较低的过电位。将该电极装入海水电解槽后，在 100 小时的测试期间内，其直流电能耗仅为 4.18 kWh/Nm3H2，且衰减可忽略不计。这些发现证明了我们的方法在工业规模海水电解方面的潜力。
{"title":"Facile Immersing Synthesis of Pt Single Atoms Supported on Sulfide for Bifunctional toward Seawater Electrolysis","authors":"Jian Shen, Guotao Yang, Tianshui Li, Wei Liu, Qihao Sha, Zheng Zhong, Yun Kuang","doi":"10.3390/catal14080477","DOIUrl":"https://doi.org/10.3390/catal14080477","url":null,"abstract":"Seawater electrolysis for hydrogen production represents a substantial opportunity to curtail production expenditures and exhibits considerable potential for various industrial applications. Platinum-based precious metals exhibit excellent activity for water electrolysis. However, their limited reserves and high costs impede their widespread use on a large scale. Single-atom catalysts, characterized by low loading and high utilization efficiency, represent a viable alternative, and the development of simple synthesis methods can facilitate their practical application. In this work, we report the facile synthesis of a single-atom Pt-loaded NiCoFeSx (Pt@NiCoFeSx) bifunctional catalytic electrode using a simple impregnation method on a nickel foam substrate. The resulting electrode exhibits low overpotentials for both HER (60 mV@10 mA cm−2) and OER (201 mV@10 mA cm−2) in alkaline seawater electrolytes. When incorporated into a seawater electrolyzer, this electrode achieves a direct current energy consumption of only 4.18 kWh/Nm3H2 over a 100 h test period with negligible decay. These findings demonstrate the potential of our approach for industrial-scale seawater electrolysis.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"35 30","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jhon Mauricio Aguirre-Cortés, A. Moral-Rodríguez, E. Bailón‐García, F. Carrasco-Marín, A. Pérez-Cadenas
BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior.
{"title":"BiVO4-Based Photocatalysts for the Degradation of Antibiotics in Wastewater: Calcination Role after Solvothermal Synthesis","authors":"Jhon Mauricio Aguirre-Cortés, A. Moral-Rodríguez, E. Bailón‐García, F. Carrasco-Marín, A. Pérez-Cadenas","doi":"10.3390/catal14080474","DOIUrl":"https://doi.org/10.3390/catal14080474","url":null,"abstract":"BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"15 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141804418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles only have catalytic activity and electron–hole pairing under ultraviolet light. Therefore, Copper(I) oxide (Cu2O)-ZnO/cellulose composites with excellent photocatalytic performance were fabricated by loading Cu2O crystals and using cellulose fiber substrate in this work. Cu2O can increase the light absorption range (including ultraviolet light and visible light) of ZnO/cellulose composites. Moreover, Cellulose fibers can improve the contact area to pollution and photostability of the Cu2O/ZnO nanoparticles, thereby enhancing the photocatalytic activity. The Cu2O-ZnO/cellulose composite showed the highest photocatalytic activity for Methyl orange (MO) degradation, which was approximately 40% and 10% times higher than those of the ZnO/cellulose and Cu2O/ZnO composites, respectively. Moreover, the degradation rate of phenol reached 100% within 80 min. The highly enhanced activity of the Cu2O-ZnO/cellulose composite is attributed to the enlargement of the light absorption range and the formation of heterojunctions between the counterparts, which effectively suppress the recombination of the photogenerated charge carriers. Overall, this work aims to improve the photocatalytic activities of ZnO/cellulose composites by loading Cu2O crystals, hoping to provide a novel and efficient photocatalyst for wastewater treatment.
{"title":"Construction of Cu2O-ZnO/Cellulose Composites for Enhancing the Photocatalytic Performance","authors":"Yuchen Li, Ming Yan, Xin Li, Jinxia Ma","doi":"10.3390/catal14080476","DOIUrl":"https://doi.org/10.3390/catal14080476","url":null,"abstract":"Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles only have catalytic activity and electron–hole pairing under ultraviolet light. Therefore, Copper(I) oxide (Cu2O)-ZnO/cellulose composites with excellent photocatalytic performance were fabricated by loading Cu2O crystals and using cellulose fiber substrate in this work. Cu2O can increase the light absorption range (including ultraviolet light and visible light) of ZnO/cellulose composites. Moreover, Cellulose fibers can improve the contact area to pollution and photostability of the Cu2O/ZnO nanoparticles, thereby enhancing the photocatalytic activity. The Cu2O-ZnO/cellulose composite showed the highest photocatalytic activity for Methyl orange (MO) degradation, which was approximately 40% and 10% times higher than those of the ZnO/cellulose and Cu2O/ZnO composites, respectively. Moreover, the degradation rate of phenol reached 100% within 80 min. The highly enhanced activity of the Cu2O-ZnO/cellulose composite is attributed to the enlargement of the light absorption range and the formation of heterojunctions between the counterparts, which effectively suppress the recombination of the photogenerated charge carriers. Overall, this work aims to improve the photocatalytic activities of ZnO/cellulose composites by loading Cu2O crystals, hoping to provide a novel and efficient photocatalyst for wastewater treatment.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"1 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lin Ma, Yan Li, Zhiquan Yu, Jie Zou, Yingying Jing, Wei Wang
The supported Ni-P catalysts (marked as s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3)) were prepared by an incipient wetness step-impregnation method, and characterized by XRD, N2 physisorption, TEM, XPS, and NH3-TPD. The catalytic hydrodeoxygenation (HDO) performance was assessed using phenol in water (5.0 wt%) or in decalin (1.0 wt%) as the feed. After the introduction of Ce, the conversion of phenol increased due to the high dispersity of the active site. However, compared to s-Ni-P/Hβ(3), the amount of total and strong acid sites of s-Ni-P/Ce-β(3) decreased, restraining the cycloisomerization of cyclohexane to form methyl-cyclopentane. Moreover, the kinetics of the APHDO and OPHDO of phenol catalyzed by s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3) were investigated.
{"title":"The Hydrodeoxygenation of Phenol over Ni-P/Hβ and Ni-P/Ce-β: Modifying the Effects in Dispersity and Acidity","authors":"Lin Ma, Yan Li, Zhiquan Yu, Jie Zou, Yingying Jing, Wei Wang","doi":"10.3390/catal14080475","DOIUrl":"https://doi.org/10.3390/catal14080475","url":null,"abstract":"The supported Ni-P catalysts (marked as s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3)) were prepared by an incipient wetness step-impregnation method, and characterized by XRD, N2 physisorption, TEM, XPS, and NH3-TPD. The catalytic hydrodeoxygenation (HDO) performance was assessed using phenol in water (5.0 wt%) or in decalin (1.0 wt%) as the feed. After the introduction of Ce, the conversion of phenol increased due to the high dispersity of the active site. However, compared to s-Ni-P/Hβ(3), the amount of total and strong acid sites of s-Ni-P/Ce-β(3) decreased, restraining the cycloisomerization of cyclohexane to form methyl-cyclopentane. Moreover, the kinetics of the APHDO and OPHDO of phenol catalyzed by s-Ni-P/Hβ(3) and s-Ni-P/Ce-β(3) were investigated.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"21 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sidra Fatima, Sana Javaid, Hira Ahmad, A. Almasoudi, Doaa F. Baamer, Omar Makram Ali, S. Carabineiro, M. Taj
This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means sodium alginate). This composite also demonstrated an exceptional antioxidant potential of approximately 89%, attributed to the synergistic effect of sodium alginate and green-synthesized Co–Zn–Ce nanoparticles (biosynthesized using Ocimum sanctum leaf extract as a reducing agent). Scanning electron microscopy revealed grain sizes of 28.6 nm for Co–Zn–Ce NPs and 25.59 nm for SA@Co–Zn–Ce nanocomposites (NCs). X-ray diffraction showed particle sizes of 16.87 nm and 15.43 nm, respectively. Co–Zn–Ce NPs exhibited a zeta potential of 1.99 mV, whereas the sodium alginate-anchored Co–Zn–Ce showed −7.99 mV. This indicated the entrapment of negatively charged ions from sodium alginate, altering the surface charge characteristics and enhancing the photocatalytic degradation of RR24. Dynamic light scattering revealed an average particle size of approximately 81 nm for SA@Co–Zn–Ce NCs, with the larger size due to the influence of water molecules in the colloidal solution affecting hydrodynamic diameter measurement. The SA@Co–Zn–Ce NCs exhibited a CO2 adsorption capacity of 3.29 mmol/g at 25 °C and 4.76 mmol/g at 40 °C, indicating temperature-dependent variations in adsorption capabilities. The specific surface area of Co–Zn–Ce oxide NPs, measured using Brunauer–Emmett–Teller (BET) analysis, was found to be 167.346 m2/g, whereas the SA@Co–Zn–Ce oxide nanocomposite showed a surface area of 24.14 m2/g. BJH analysis revealed average pore diameters of 34.60 Å for Co–Zn–Ce oxide NPs and 9.26 Å for SA@Co–Zn–Ce oxide NCs. Although the immobilization of sodium alginate on Co–Zn–Ce oxide NPs did not increase the adsorption sites and porosity of the composite, as evidenced by the N2 adsorption–desorption isotherms, the SA@Co–Zn–Ce oxide NCs still demonstrated a high photocatalytic degradation efficiency of RR24.
{"title":"Facile Synthesis of Sodium Alginate (SA)-Based Quaternary Bio-Nanocomposite (SA@Co-Zn-Ce) for Antioxidant Activity and Photocatalytic Degradation of Reactive Red 24","authors":"Sidra Fatima, Sana Javaid, Hira Ahmad, A. Almasoudi, Doaa F. Baamer, Omar Makram Ali, S. Carabineiro, M. Taj","doi":"10.3390/catal14080471","DOIUrl":"https://doi.org/10.3390/catal14080471","url":null,"abstract":"This study introduces a new strategy for the environmentally friendly catalytic degradation of Reactive Red 24 (RR24) dye using sunlight. We developed a cost-effective quaternary nanocomposite by immobilizing a sodium alginate biopolymer over bioengineered Co-Zn-Ce nanoparticles, forming an SA@Co–Zn–Ce nanocomposite (where SA means sodium alginate). This composite also demonstrated an exceptional antioxidant potential of approximately 89%, attributed to the synergistic effect of sodium alginate and green-synthesized Co–Zn–Ce nanoparticles (biosynthesized using Ocimum sanctum leaf extract as a reducing agent). Scanning electron microscopy revealed grain sizes of 28.6 nm for Co–Zn–Ce NPs and 25.59 nm for SA@Co–Zn–Ce nanocomposites (NCs). X-ray diffraction showed particle sizes of 16.87 nm and 15.43 nm, respectively. Co–Zn–Ce NPs exhibited a zeta potential of 1.99 mV, whereas the sodium alginate-anchored Co–Zn–Ce showed −7.99 mV. This indicated the entrapment of negatively charged ions from sodium alginate, altering the surface charge characteristics and enhancing the photocatalytic degradation of RR24. Dynamic light scattering revealed an average particle size of approximately 81 nm for SA@Co–Zn–Ce NCs, with the larger size due to the influence of water molecules in the colloidal solution affecting hydrodynamic diameter measurement. The SA@Co–Zn–Ce NCs exhibited a CO2 adsorption capacity of 3.29 mmol/g at 25 °C and 4.76 mmol/g at 40 °C, indicating temperature-dependent variations in adsorption capabilities. The specific surface area of Co–Zn–Ce oxide NPs, measured using Brunauer–Emmett–Teller (BET) analysis, was found to be 167.346 m2/g, whereas the SA@Co–Zn–Ce oxide nanocomposite showed a surface area of 24.14 m2/g. BJH analysis revealed average pore diameters of 34.60 Å for Co–Zn–Ce oxide NPs and 9.26 Å for SA@Co–Zn–Ce oxide NCs. Although the immobilization of sodium alginate on Co–Zn–Ce oxide NPs did not increase the adsorption sites and porosity of the composite, as evidenced by the N2 adsorption–desorption isotherms, the SA@Co–Zn–Ce oxide NCs still demonstrated a high photocatalytic degradation efficiency of RR24.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"5 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Shafiq, Ujin Jeong, Yunseon Han, Youngsik Kim, Joonmin Lee, Beom Soo Kim
To promote environmental development and sustain resource circularity, recycling metals from electronic waste is essential. Electronic waste is a significant secondary source of metals, with its production increasing rapidly and most remaining unrecycled. In solar panels, copper is the second-most-valuable metal after silver. We propose an innovative method to recycle copper from waste solar panels and convert it into copper oxide nanoparticles (CuONPs) using a green synthesis method. Synthesizing CuONPs is advantageous due to their large surface area compared to bulk material. Nitric acid, a strong oxidizing agent, was used to leach copper from solid copper wires in waste solar panels. A green synthesis method, following a bottom-up approach, was employed using Piper nigrum fruit extract to synthesize CuONPs. The synthesized nanoparticles were characterized using various qualitative and quantitative techniques. Spectroscopic analysis confirmed the formation of CuONPs, and transmission electron microscopy revealed that the nanoparticles were spherical with sizes up to 60 nm. Biomolecules from the Piper nigrum extract were detected on the surface of the crystalline CuONPs. These nanoparticles exhibited antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using a well-diffusion method, showing a larger zone of inhibition for E. coli compared to S. aureus. This research demonstrates the complete recovery of copper from waste solar panels and its conversion into useful CuONPs, which have potential medicinal applications.
{"title":"Green Synthesis of Copper Oxide Nanoparticles from Waste Solar Panels Using Piper nigrum Fruit Extract and Their Antibacterial Activity","authors":"A. Shafiq, Ujin Jeong, Yunseon Han, Youngsik Kim, Joonmin Lee, Beom Soo Kim","doi":"10.3390/catal14080472","DOIUrl":"https://doi.org/10.3390/catal14080472","url":null,"abstract":"To promote environmental development and sustain resource circularity, recycling metals from electronic waste is essential. Electronic waste is a significant secondary source of metals, with its production increasing rapidly and most remaining unrecycled. In solar panels, copper is the second-most-valuable metal after silver. We propose an innovative method to recycle copper from waste solar panels and convert it into copper oxide nanoparticles (CuONPs) using a green synthesis method. Synthesizing CuONPs is advantageous due to their large surface area compared to bulk material. Nitric acid, a strong oxidizing agent, was used to leach copper from solid copper wires in waste solar panels. A green synthesis method, following a bottom-up approach, was employed using Piper nigrum fruit extract to synthesize CuONPs. The synthesized nanoparticles were characterized using various qualitative and quantitative techniques. Spectroscopic analysis confirmed the formation of CuONPs, and transmission electron microscopy revealed that the nanoparticles were spherical with sizes up to 60 nm. Biomolecules from the Piper nigrum extract were detected on the surface of the crystalline CuONPs. These nanoparticles exhibited antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using a well-diffusion method, showing a larger zone of inhibition for E. coli compared to S. aureus. This research demonstrates the complete recovery of copper from waste solar panels and its conversion into useful CuONPs, which have potential medicinal applications.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"55 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of mesopores and macropores existed in the wall of the hydrogel lamellae. This network structure reduced the diffusion resistance of the hydrogel to the target substrate. The relative activity of the resulting Lac-CD-PAA could be maintained at 35.8% after six cycles of use. Lac-CD-PAA exhibited higher thermal and chemical stability compared to free laccase. The negative charge on the surface of Lac-CD-PAA gives it the ability to pretreat cationic dyes. In six consecutive methylene blue decolorization tests, Lac-CD-PAA decolorized better than free laccase. The results showed that the prepared β-cyclodextrin-based composite hydrogel was a good carrier for laccase.
{"title":"Immobilization of Laccase in β-Cyclodextrin Composite Hydrogel for Efficient Degradation of Dye Pollutants","authors":"Hong Zhang, Zhi Wang, Fengxi Li, Lei Wang, Bo Ren","doi":"10.3390/catal14080473","DOIUrl":"https://doi.org/10.3390/catal14080473","url":null,"abstract":"A stable and efficient biocatalyst was prepared by encapsulating Trametes versicolor laccase using an acrylic acid-grafted β-cyclodextrin hydrogel (Lac-CD-PAA). Scanning electron microscopy and nitrogen adsorption-desorption experiments showed that there were regularly distributed channels in the spongy Lac-CD-PAA. In addition, a large number of mesopores and macropores existed in the wall of the hydrogel lamellae. This network structure reduced the diffusion resistance of the hydrogel to the target substrate. The relative activity of the resulting Lac-CD-PAA could be maintained at 35.8% after six cycles of use. Lac-CD-PAA exhibited higher thermal and chemical stability compared to free laccase. The negative charge on the surface of Lac-CD-PAA gives it the ability to pretreat cationic dyes. In six consecutive methylene blue decolorization tests, Lac-CD-PAA decolorized better than free laccase. The results showed that the prepared β-cyclodextrin-based composite hydrogel was a good carrier for laccase.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"28 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chenyang Li, Jian Yang, Chongbin Zhang, Cong Wang, Chen Lyu, Kai Fan
In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4, catalysts were prepared and used for the catalytic reduction of CO2 to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO2, which is more beneficial for catalyzing CO2. Among them, Au-10%Cu/C3N4 exhibited good reducibility and strong basic sites, as demonstrated by H2-TPR and CO2-TPD, with the conversion rates for CO2, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg−1·h−1 (0.39 μmol·g−1s−1), and 59.77%, respectively.
本文通过水热合成法成功地将金和铜纳米粒子负载到多孔 g-C3N4 材料上。通过调整铜的比例，制备了 Au-5%Cu/C3N4、Au-10%Cu/C3N4 和 Au-15%Cu/C3N4 催化剂，并将其用于催化 CO2 还原成甲醇。利用高分辨率 XPS 光谱进行的表征分析表明，随着铜掺杂量的增加，铜表面的电子云密度先增大后减小。金原子的电子转移到铜原子上，导致铜表面积累了更多的负电荷，促进了 CO2 中带部分正电荷的 C 的吸附，更有利于催化 CO2。其中，Au-10%Cu/C3N4 表现出良好的还原性和较强的碱性位点，H2-TPR 和 CO2-TPD 均证明了这一点，其 CO2 转化率、甲醇产率和甲醇选择性分别为 11.58%、41.29 g-kg-1-h-1（0.39 μmol-g-1s-1）和 59.77%。
{"title":"Study on Catalytic Performance in CO2 Hydrogenation to Methanol over Au–Cu/C3N4 Catalysts","authors":"Chenyang Li, Jian Yang, Chongbin Zhang, Cong Wang, Chen Lyu, Kai Fan","doi":"10.3390/catal14080470","DOIUrl":"https://doi.org/10.3390/catal14080470","url":null,"abstract":"In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4, catalysts were prepared and used for the catalytic reduction of CO2 to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO2, which is more beneficial for catalyzing CO2. Among them, Au-10%Cu/C3N4 exhibited good reducibility and strong basic sites, as demonstrated by H2-TPR and CO2-TPD, with the conversion rates for CO2, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg−1·h−1 (0.39 μmol·g−1s−1), and 59.77%, respectively.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"68 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141813008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Stoyanova, H. Hitkova, N. Kaneva, A. Bachvarova-Nedelcheva, R. Iordanova, Polya Marinovska
The current study aims to synthesize and analyze both pure and La-doped TiO2, and evaluate the photocatalytic and antibacterial activity of as-prepared samples. Doped and undoped samples were prepared by the non-hydrolytic sol–gel method from titanium(IV) chloride, benzyl alcohol, and lanthanum(III) nitrate followed by thermal treatment. Lanthanum content in synthesized samples was 0.4, 1, and 5 mol%. The resulting nanopowders’ structure and morphology were described using XRD, IR, and UV–Vis analysis. The average particle sizes of pure and doped TiO2 were about 6–15 nm and anatase was found to be a dominant crystalline phase in the samples. It was observed that particle sizes decreased on increasing La content. The photocatalytic activity of the pure and La-doped sol–gel powders was estimated in the decomposition of paracetamol in distilled water using ultraviolet light illumination. Doping with lanthanum ions has been shown to increase the photocatalytic properties on the degradation of paracetamol. Furthermore, the annealed catalysts (pure and La3+ doped) showed increased photocatalytic activity and degradation of the analgesic in comparison with non-annealed materials. In both cases, the highest photocatalytic efficiency is observed at the optimal La3+ (1 mol%) concentration. The antimicrobial activity of 1 mol% La/TiO2 was tested against a reference strain E. coli in the presence of ultraviolet light and in dark conditions. The number of viable bacterial cells was determined by a spread plate method, and kill curves were performed. The results showed that photoactivated 1 mol% La/TiO2 exhibited a strong bactericidal effect, and in concentration, 1 mg/mL efficiently killed bacteria at an initial cell density of about 105 colony forming units in 1 mL within 15 min.
{"title":"Photocatalytic Degradation of Paracetamol and Antibacterial Activity of La-Modified TiO2 Obtained by Non-Hydrolytic Sol–Gel Route","authors":"A. Stoyanova, H. Hitkova, N. Kaneva, A. Bachvarova-Nedelcheva, R. Iordanova, Polya Marinovska","doi":"10.3390/catal14080469","DOIUrl":"https://doi.org/10.3390/catal14080469","url":null,"abstract":"The current study aims to synthesize and analyze both pure and La-doped TiO2, and evaluate the photocatalytic and antibacterial activity of as-prepared samples. Doped and undoped samples were prepared by the non-hydrolytic sol–gel method from titanium(IV) chloride, benzyl alcohol, and lanthanum(III) nitrate followed by thermal treatment. Lanthanum content in synthesized samples was 0.4, 1, and 5 mol%. The resulting nanopowders’ structure and morphology were described using XRD, IR, and UV–Vis analysis. The average particle sizes of pure and doped TiO2 were about 6–15 nm and anatase was found to be a dominant crystalline phase in the samples. It was observed that particle sizes decreased on increasing La content. The photocatalytic activity of the pure and La-doped sol–gel powders was estimated in the decomposition of paracetamol in distilled water using ultraviolet light illumination. Doping with lanthanum ions has been shown to increase the photocatalytic properties on the degradation of paracetamol. Furthermore, the annealed catalysts (pure and La3+ doped) showed increased photocatalytic activity and degradation of the analgesic in comparison with non-annealed materials. In both cases, the highest photocatalytic efficiency is observed at the optimal La3+ (1 mol%) concentration. The antimicrobial activity of 1 mol% La/TiO2 was tested against a reference strain E. coli in the presence of ultraviolet light and in dark conditions. The number of viable bacterial cells was determined by a spread plate method, and kill curves were performed. The results showed that photoactivated 1 mol% La/TiO2 exhibited a strong bactericidal effect, and in concentration, 1 mg/mL efficiently killed bacteria at an initial cell density of about 105 colony forming units in 1 mL within 15 min.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"47 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141813379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanism of the electrochemical CO2 reduction reaction on a Cu(110) surface has yet to be fully revealed. In this work, based on first-principles calculations, we investigate the mechanisms of the CO2 reduction reaction to produce C1 (including one C atom) and C2 (including two C atoms) products on a Cu(110) surface. The results show that CH4 and C2H5OH are the main C1 and C2 products on the Cu(110) surface, respectively. CH4 is produced along the pathway CO2 → COOH* → CO* → CHO* → CH2O* → CH3O* → CH4. C2H5OH is produced via the C-C coupling pathway between CO* and CH2O* intermediates, which is the key reaction step. This is because CO* and CH2O* coupling to CO-CH2O* has the lowest barrier among the CHxO* (x = 0–2) coupling pathways. Therefore, it is the most likely C-C coupling pathway. Further, CO-CH2O* is gradually hydrogenated to C2H5OH along the following pathway: CO-CH2O* → CHO-CH2O* → CHOH-CH2* → CH2OH-CH2* → CH2OH-CH3* → C2H5OH.
{"title":"A First-Principles Study on the Reaction Mechanisms of Electrochemical CO2 Reduction to C1 and C2 Products on Cu(110)","authors":"Yangyang Xu, Lixin Zhang","doi":"10.3390/catal14070468","DOIUrl":"https://doi.org/10.3390/catal14070468","url":null,"abstract":"The mechanism of the electrochemical CO2 reduction reaction on a Cu(110) surface has yet to be fully revealed. In this work, based on first-principles calculations, we investigate the mechanisms of the CO2 reduction reaction to produce C1 (including one C atom) and C2 (including two C atoms) products on a Cu(110) surface. The results show that CH4 and C2H5OH are the main C1 and C2 products on the Cu(110) surface, respectively. CH4 is produced along the pathway CO2 → COOH* → CO* → CHO* → CH2O* → CH3O* → CH4. C2H5OH is produced via the C-C coupling pathway between CO* and CH2O* intermediates, which is the key reaction step. This is because CO* and CH2O* coupling to CO-CH2O* has the lowest barrier among the CHxO* (x = 0–2) coupling pathways. Therefore, it is the most likely C-C coupling pathway. Further, CO-CH2O* is gradually hydrogenated to C2H5OH along the following pathway: CO-CH2O* → CHO-CH2O* → CHOH-CH2* → CH2OH-CH2* → CH2OH-CH3* → C2H5OH.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141815304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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