The article discusses a study conducted at the Center for Functional Nanomaterials in Brookhaven, United States, where researchers explored the impact of temperature on photoelectrochemical (PEC) water splitting using a bismuth vanadate (BiVO4) photoanode. By immersing cells made of metal oxides in an electrolyte and exposing them to sunlight, the cells react to split water into hydrogen and oxygen. The research revealed that elevated temperatures in the electrolyte can enhance the activity of a bismuth-vanadate electrode by 40%, leading to increased hydrogen production. The study sheds light on how thermal energy contributes to improving charge carrier separation in the bulk of BiVO4, highlighting the importance of temperature optimization in solar hydrogen generation. The findings also showcase the impact of hole scavengers on the surface reconstruction of the photoelectrode, which resulted in a 40% improvement in photocurrent density and a positive shift in photocurrent onset. This research not only deepens our understanding of metal oxide cells but also provides a foundation for developing materials that can enhance the efficiency of solar water splitting, potentially advancing the technology towards commercial viability. The work was funded by the Department of Energy and utilized resources from multiple facilities at the Center for Functional Nanomaterials.