In Situ Transition of a Nickel Metal–Organic Framework on TiO2 Photoanode towards Urea Photoelectrolysis

Photoelectrochemical (PEC) urea splitting is of great significance for wastewater remediation and hydrogen production with low energy consumption simultaneously. Nickel hydroxides as electrocatalysts have been widely investigated electrolysis. However, it an open question how to synthesize highly catalytic Ni(OH)2 the PEC splitting. Herein, we take advantage instability metal–organic frameworks (MOFs) perform in situ synthesis catalysts on surface TiO2 nanorod arrays. This transformed (T-Ni(OH)2) possesses a superior activity water/urea comparison prepared by impregnation method. The transition Ni-MOF accomplished through electrochemical treatment under AM1.5G illumination KOH-and-urea mixed electrolyte. specific mechanism Ni-MOFs substitution ligands OH− 1 M KOH electrolyte successive phase transition. T-Ni(OH)2@TiO2 photoanode delivers high photocurrent density 1.22 mA cm−2 at 1.23 VRHE, which 4.7 times that Ni(OH)2@TiO2 onset potential negatively shifted 118 mV TiO2. Moreover, decline during continuous test can be recovered after light treatments.