Realization of sustainable hydrogen production via photoelectrochemical (PEC) water splitting is contingent on developing efficient and low-cost photoelectrode. Sb2Se3 recently receives great interest as a promising low-cost light-absorbing material for solar energy conversion. In this talk, we will present a synthetic methodology to produce efficient Sb2Se3 nanostructure photocathodes by a simple spin-coating of Sb-Se molecular ink. The Sb-Se molecular ink is prepared by using the solvent mixture of thioglycolic acid (TGA) and ethanolamine (EA) and the aspect ratio of 1-D Sb2Se3 nanostructures can be controlled by adjusting the relative mixing ratio of TGA and EA. After the deposition of TiO2 and Pt, an appropriately oriented Sb2Se3 nanostructure array exhibits a significantly enhanced PEC performance; the photocurrent reached 12.5 mA cm-2 at 0 V versus reversible hydrogen electrode under AM 1.5 G illumination. The role of carboxylate nucleophile enabling the unique 1-D nanostructures will be elucidated by liquid Raman spectroscopy in conjunction with the observation of the morphological evolution. In addition, the strengths and limitations of Sb2Se3 based photocathode will be discussed with various analyses including incident photon-to-current conversion efficiency, THz spectroscopy, and time-resolved photoluminescence.