Photoelectrochemical (PEC) water splitting is one of the ideal alternatives for hydrogen production from clean and abundant solar energy. La5Ti2CuS5O7 (LTC) was reported as a visible light responded oxysulfide semiconductor whose wavelength of absorption edge was at 650 nm equal with a band gap value of 1.9 eV [1-3]. Furthermore, the abundance of Ti, Cu and La element in the earth&’s crustal rocks are 6320, 68 and 35 ppm respectively, which is much higher than the widely studied PEC materials such as Ga (19 ppm) and In (0.24 ppm) . We had reported that LTC exhibit photocatalytic activity for both water reduction and oxidation under visible light irradiation in the presence of sacrificial reagents [2,3]. These results indicate that LTC has the potential for overall water splitting to utilize a large portion of sunlight (lambda;< 650 nm) as a photocatalyst. Then, the LTC thin-film photoelectrode was fabricated by a novel particle transfer (PT) technology . The PEC water splitting reaction was carried in a commonly used three-electrode system under visible light irradiation. The current-voltage curve for LTC thin film electrode under intermittent visible-light irradiation showed a clear photocathodic current, which implied a p-type semiconductor character. The correlation between the amount of H2 evolution and photocatodic current showed a nearly 100% faradic efficiency on the LTC photoelectrode. Then, the zero-bias PEC water splitting was carried out by combining the LTC photocathode with other photoanode prepared by the PT method, which finally accomplished stoichiometric H2 and O2 production from water under visible light irradiation.
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