Rationally designed, efficient, and earth-abundant Ni-Fe cocatalysts for solar hydrogen generation

TitleRationally designed, efficient, and earth-abundant Ni-Fe cocatalysts for solar hydrogen generation
Publication TypeJournal Article
Year of Publication2021
AuthorsTudu, B, Nalajala, N, Reddy, KPrabhakar, Saikia, P, Gopinath, CS
JournalACS Sustainable Chemistry & Engineering
Volume9
Issue41
Pagination13915-13925
Date PublishedOCT
Type of ArticleArticle
ISSN2168-0485
KeywordsCocatalyst, Hydrogen, Ni-Fe alloy, solar energy, TiO2, water splitting
AbstractDeveloping highly efficient and affordable catalysts for solar hydrogen (H-2) generation is crucial, and employing a cocatalyst from earth-abundant elements has a critical role to play. In this context, different compositions of earth-abundant Ni-Fe alloy (1:1, 1:3, and 3:1) have been prepared by hydrothermal method; subsequently, 1 wt % of these Ni-Fe cocatalysts were integrated with TiO2-P25 and thoroughly characterized. The resultant catalysts have been evaluated for solar H-2 production, in powder and thin film forms, under one sun condition and in direct sunlight. Interestingly, all the catalysts in the thin film form exhibit superior hydrogen yield (HY), up to 27 times higher activity than its powder counterpart. Among the photocatalysts, Ni-Fe/TiO2 (3:1 = Ni/Fe; NFT31) composition exhibits the best HY in thin film (8.27 mmol.h(-1).g(-1)) and exceeds all other compositions of catalyst. It is also to be reported that HY measured for the powder form with 1 mg shows 3-17 times higher activity than that measured with 25 mg. This is mainly attributed to effective solar light absorption with a smaller amount of photocatalyst either spread over large area in a thin film form or well-dispersed in suspension forms. Furthermore, the enhanced activity obtained with Ni-Fe/TiO2 photocatalysts is also ascribed to strong electronic integration of Ni-Fe cocatalyst with TiO2 and higher performance obtained with a thin film is attributed to increased charge carrier generation and subsequent charge separation and effective utilization. A decrease in work function of TiO2 by 0.6 eV was observed after its integration with cocatalyst in NFT31.
DOI10.1021/acssuschemeng.1c05158
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)8.198
Divison category: 
Catalysis and Inorganic Chemistry

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