Artificial photosynthesis is considered as one of the most promising strategies to store solar energy.In this symposium,I will talk about our recent works on solar water splitting and CO2 reduction in both photoelectrochemical(PEC)and photovoltaic(PV)approaches.In the PEC approach,we obtained Cu2O photocathodes with a photocurrent density of 10 mA cm-2 and an onset potential of 1 V versus reversible hydrogen electrode by marrying nanowire electrode structure and Ga2O3 buffer layer.