Effect of Synthesis Method on Reaction Mechanism for Hydrogen Evolution over Cu_xO_y/TiO₂ Photocatalysts: A Kinetic Analysis.

ABSTRACT: The existing literature survey reports rare and conflicting studies on the effect of the preparation method of metal-based semiconductor photocatalysts on structural/morphological features, electronic properties, and kinetics regulating the photocatalytic H₂ generation reaction. In this investigation, we compare the different copper/titania-based photocatalysts for H₂ generation synthesized via distinct methods (i.e., photodeposition and impregnation). Our study aims to establish a stringent correlation between physicochemical/electronic properties and photocatalytic performances for H₂ generation based on material characterization and kinetic modeling of the experimental outcomes. Estimating unknown kinetic parameters, such as charge recombination rate and quantum yield, suggests a mechanism regulating charge carrier lifetime depending on copper distribution on the TiO₂ surface. We demonstrate that H₂ generation photoefficiency recorded over impregnated Cu_xO_y/TiO₂ is related to an even distribution of Cu(0)/Cu(I) on TiO₂, and the formation of an Ohmic junction concertedly extended charge carrier lifetime and separation. The outcomes of the kinetic analysis and the related modeling investigation underpin photocatalyst physicochemical and electronic properties. Overall, the present study lays the groundwork for the future design of metal-based semiconductor photocatalysts with high photoefficiencies for H₂ evolution.

SUBMITTER: Clarizia L 

PROVIDER: S-EPMC9916258 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature