Photoelectrodeposition of Pt nanoparticles on Sb2Se3 photocathodes for enhanced water splitting

•PED method for Pt deposition provides better performance for the catalyst.•PED improves photocurrent density compared with the electrodeposition method.•It is obtained different nucleation and growth kinetics comparing ED and PED.•Faster and good distribution of Pt nanoparticles is achieved using PED. One of the biggest challenges around photochemical materials is to develop highly active and stable catalysts, if possible, with a simple synthesis methodology. This study presents the photoactivity of Sb2Se3 semiconductor containing Pt nanoparticles obtained with a fast deposition rate. The deposition of Pt nanoparticles using the electrodeposition (ED) and photoelectrodeposition (PED) methods was investigated. Even with the same electrodeposition charge, the photocatalyst prepared using PED resulted in a material with photocurrent density almost three times higher than the one prepared through ED. There is a difference in the nucleation and growth kinetics of Pt nanoparticles between the two methods. The Pt growth using ED was characterized by the agglomeration of Pt with consequent formation of larger metal particles, while PED generated new sites for the metal deposition, allowing a better distribution of Pt on the surface of the semiconductor and improving the photocurrent density, charge transfer, and photoconversion of the photocatalyst. [Display omitted]