A transparent CdS@TiO2 nanotextile photoanode with boosted photoelectrocatalytic efficiency and stability†
In the present work, we report the exploration of a transparent CdS@TiO2 nanotextile photoanode with boosted photoelectrocatalytic (PEC) efficiency and stability, by the controllable coating of an amorphous TiO2 ultrathin layer via the atomic layer deposition (ALD) technique. The optimal CdS@TiO2 nanotextile photoanode with a 3.5 nm TiO2 ultrathin layer exhibits a photocurrent density of 1.8 mA cm−2 at 0 V vs. RHE, which is 11 times higher than that of the pristine CdS counterpart. The photocatalytic H2 evolution rate of CdS@TiO2 ranges up to 47.5 mmol g−1 h−1, which is superior to those reported for one-dimensional CdS-based counterparts. Moreover, the photocurrent of CdS@TiO2 nanotextile photoanodes shows only 9% decay after 9 h, suggesting its profoundly enhanced PEC stability, in comparison with that of pristine CdS photoanodes (almost down to zero after 3 hours). It is verified that the introduced TiO2 nanoshells could limit the charge recombination, facilitate the charge separation, reduce the charge transfer resistance, and enhance the wettability of the electrodes, resulting in their significantly enhanced PEC performance.