Design of Nd-SrTiO3/SrCO3@Ag2O Z-scheme heterojunction with the dual internal electric field for piezo-photocatalytic removal of pollutants
Jiayi Huang, Hongji Li, Chunjiao Hu, Jingmei Li, Xiulong Li, Dandan Wang, D.-H. Ju
Abstract
With the increasing severity of environmental pollution problems, developing efficient and low-cost pollution control technologies has become an urgent task. This study designed and prepared a novel Nd-SrTiO 3 /SrCO 3 @Ag 2 O (Nd-SSTO/Ag 2 O) dual internal electric field material for piezoelectric photocatalytic removal of pollutants from water. Under simulated sunlight irradiation, the material exhibited excellent photocatalytic activity . Among them, under single visible light irradiation and single ultrasound vibration, the degradation rate of RhB by 2.5 % Nd-SSTO/Ag 2 O-0.2 only reached 22.4 % and 25.6 % in 1 h, respectively. However, when visible light and ultrasound vibration act simultaneously, the degradation rate of RhB by 2.5 % Nd-SSTO/Ag 2 O-0.2 reached 95.1 % in 1 h with the reaction rate constants being 8.86 times and 1.64 times those of SSTO and Ag 2 O respectively. Furthermore, after four cyclic experiments, the degradation efficiency of RhB by 2.5 % Nd-SSTO/Ag 2 O-0.2 remained above 90 %. Additionally, ICP analysis revealed that the amount of catalyst elements released into the solution during the degradation process was extremely low, indicating that the prepared 2.5 % Nd-SSTO/Ag 2 O-0.2 catalyst possesses good stability. Through Nd doping, the light absorption range of SSTO was extended from the ultraviolet region to the visible region. After inducing Ag 2 O, a Nd-SSTO/Ag 2 O Z-scheme heterojunction was formed with the dual internal electric field, which not only expanded the carrier transmission channel but also improved the photo-induced carrier separation, allowing more e − and h + to participate in the photocatalytic degradation reaction. Additionally, the piezoelectric characteristics of SrTiO 3 (STO) further accelerated the migration of e − -h + pairs. This study opens up a new idea for the development and preparation of high-efficiency piezoelectric photocatalytic materials, and also provides a potential technical approach for environmental pollution control .