Enhanced stability and activity towards photocatalytic CO 2 reduction via supercycle ALD of Cu and TiO 2

Enhanced photocatalytic performance and excellent stability are usually regarded contradictory during photocatalytic reaction. In this study, supercycle ALD was employed to achieve superior performance and stability simultaneously for the system of TiO 2 @Cu during CO 2 reduction reaction, which was unattainable by post-deposition TiO 2, a commonly-employed technique for enhancing stability. More oxygen vacancy, partially-covered Cu species as well as well-maintained charge separation capability of alternatively-deposited TiO 2 @(2Cu + 2TiO 2 ) × 25 could be the reason for enhanced activity and stability as suggested by a series of characterizations such as Single-particle TRPL and Single-particle PL. Experimental data also suggested unselective and mixed-layer deposition of TiO 2 and Cu loaded in the mode of alternative-deposition. The method proved in our study could be applicable in synthesizing other ALD-prepared catalysts with enhanced performance and stability, which will be a big step forward towards comprehensively utilizing the potential of ALD technique in the field of photocatalysis.