Water-mediated Selectivity Control of Ch 3 oh Versus CO/CH 4 in CO 2 Photoreduction on Single-Atom Implanted Nanotube Arrays.

Controllable methanol production in artificial photosynthesis is highly desirable due to its high energy density and ease of storage. Herein, single atom Fe was implanted into TiO 2 /SrTiO 3 (TSr) nanotube arrays by a two-step anodization strategy and Sr-induced crystallization process. The resulting Fe-TSr with both single Fe reduction centers and dominant oxidation facets (001) contributes to highly efficient CO 2 photoreduction and water oxidation for controlled production of CH 3 OH and CO/CH 4 . The methanol yield can reach to as high as 154.20 μmol g cat -1 h -1 with 98.90% selectivity by immersing all the catalyst in pure water, and the total yield of gaseous products CO/CH 4 was 147.48 μmol g cat -1 h -1 with > 99.99% selectivity when the catalyst completely outside water. This CH 3 OH yield is 50 and 3 times higher than that of TiO 2 and TSr nanotube arrays and stands among all the state-of-the-art catalysts. The facile gas-solid and gas-liquid-solid phase switch can selectively control CH 3 OH production from ∼0% (above H 2 O) to 98.90% (in H 2 O) via slowly immersing the catalyst into water, where abundant •OH and H 2 O around Fe sites play important role in selective CH 3 OH production. This work highlights a new insight for water-mediated CO 2 photoreduction to controllably produce important chemical feedstock of CH 3 OH. This article is protected by copyright. All rights reserved.