Construction of γ-graphyne and strontium titanate heterostructures for highly efficient photocatalytic degradation

Abstract

As a new member of the carbon family, γ-graphyne is combined with SrTiO3 for the first time in this paper, and a series of SrTiO3/γ-graphyne heterostructures are synthesized by a simple impregnation method. The as-prepared heterostructures are investigated by a series of characterizations, and the optimal content of γ-graphyne (γ-GY) is determined to be 1.0 wt%. After γ-GY modification, the maximum photocurrent and current density are enhanced by 30 and 5 folds, respectively, and the excitation and separation of photogenerated charges enhanced. In addition, the degradation of methylene blue by the heterostructured SrTiO3/γ-graphyne under visible light irradiation reached 88 % in 30 min with a photocatalytic rate of 6.277 × 10−2min−1, enhanced by 3.04 times compared with SrTiO3. The degradation properties are also proved by Rhodamine B degradation tests. The excellent stability and recyclability of the catalysts are proved. And h+, •O2−, and •OH are demonstrated to play roles in the reaction process, with •OH being the main active substance. A possible photocatalytic mechanism is further suggested. This work sheds light on the design of γ-GY modified composites for photoelectrochemical and photocatalytic applications.