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Experimental studies of the surface reactions of photocatalyzed or photoelectrocatalyzed water oxidation on rutile, anatase, and brookite TiO2 show significant differences between the three polymor...

Deposition of cocatalyst is an efficient way for photocatalytic water splitting to improve solar energy conversion efficiency, and its deposition method has been known to make a great effect. In this work, we introduced a sulfurization-assisted deposition method to load earth-abundant cobalt cocatalyst for the purpose of promoting water oxidation performance of Sm2Ti2S2O5 oxysulfide that is characterized with wide visible light absorption. The cobalt deposition introduced here undergoes first formation of CoSx by sulfurization at high temperature and subsequent conversion into CoOx by calcinations in air. Compared to conventionally impregnated cobalt or IrO2 colloids, the sulfurization-assisted cobalt deposition well maintains structure of photocatalyst and inhibits the formation of defect sites leading to better separation of photogenerated carriers and water oxidation performance. The apparent quantum efficiency of the optimized sample reaches 5.0% at 420 nm. The sulfurization-assisted deposition actual...

The oxygen evolution is kinetically the key step in the photocatalytic water splitting. Cocatalysts could lower the activation potential for O2 evolution. However, the cocatalyst for O2 evolution has been less investigated, and few effective cocatalysts were reported. This paper reports that the O2 evolution rate of photocatalytic water splitting under visible light irradiation can be significantly enhanced when the electrocatalyst cobalt–phosphate (denoted as CoPi) was deposited on BiVO4. The photocurrent density is also greatly enhanced by loading CoPi on BiVO4 electrode, and this enhancement in performance shows the similar trend between the photocatalytic activity and photocurrent density. We also found that this tendency is true for BiVO4 loaded with a series of different electrocatalysts as the cocatalysts. These results demonstrate that an effective electrocatalyst of water oxidation can be also an effective cocatalyst for O2 evolution from photocatalytic water oxidation. By depositing the CoPi as ...