Proximity of defects and Ti-H on hydrogenated SrTiO3 mediated photocatalytic reduction of CO2 to C2H2

Photocatalytic converting CO 2 into C 2 products is highly desirable but is extremely sensitive to catalyst structure. In this work, Ti-H species and oxygen vacancies are simultaneously integrated on hydrogenated SrTiO 3 surface by thermally treating with NaBH 4 , which promotes the activation of CO 2 into HCOO - and CO* intermediates. The proximity of oxygen vacancies and Ti-H species contributes to the C-C coupling of intermediates into acetylene (C 2 H 2 ) products. To the best of our knowledge, this is the first example for the photocatalytic CO 2 reduction into C 2 H 2 main products. The optimal hydrogenated SrTiO 3 has the C 2 H 2 yield of 39.0 μmol·g −1 with a 76.0 % selectivity among C 2 products. Therefore, this work provides an approach of designing the adjacent active sites for photocatalytic CO 2 conversion into C 2+ products.