A transparent CdS@TiO2 nanotextile photoanode with boosted photoelectrocatalytic efficiency and stability

Abstract

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.