Photoelectrochemical (PEC) water splitting has been considered as a promising approach for producing renewable hydrogen from water and sunlight. To realize scalable hydrogen production with this approach, it is crucial to develop simple methods for the preparation of cost-effective semiconducting materials. Sb2Se3 has recently gained significant attention as a candidate for PEC water splitting and solar cells, benefiting from its excellent optoelectronic and electro(chemical) properties, such as high absorption coefficient (α > 10 5 cm -1 in the nearinfrared and visible region), 2 suitable band gap (1.1-1.3 eV), good carrier mobility (∼10 cm 2 V -1 s -1 ), low cost, and photo-corrosion resistance. For PEC water splitting, the photocurrent density (Jph) of Sb2Se3 photocathodes has been extensively improved from 2 mA cm -2 to 35.7 mA cm -2 at 0 V versus a reversible hydrogen electrode (VRHE), nearly approaching the maximum theoretical value of 40.9 mA cm -2 . However, the photovoltage of Sb2Se3 photocathodes is still far behind the theoretical maximum value, attributed to a rich defect chemistry stemming from the two nonequivalent Sb and three nonequivalent Se atomic sites.