Sol-gel synthesis of upconversion perovskite/attapulgite heterostructures for photocatalytic fixation of nitrogen

Ammonia synthesis consumes large amounts of energy in traditional industry and causes considerable air pollution to the atmosphere. Therefore, developing green strategies and novel catalysis for NH3 synthesis under ambient conditions using renewable energy is strongly desired. In this work, Er-doped lanthanum cobaltite/attapulgite composites (LaCoO3:Er3+/ATP) were prepared by a sol-gel method. The influence of the Er doping ratio and LaCoO3:Er3+ loading amount on the generation rate of ammonia under visible-light irradiation were investigated. The results show that Er3+-doped LaCoO3 can convert visible light into ultraviolet light and reach the highest conversion rate when the doping amount of the Er element is 6 mol%, which enhances the utilization of solar energy. ATP contributes to the adsorption of N-2 and the Co dopant weakens the N equivalent to N bond favoring the activation of N-2. Moreover, a direct Z-scheme heterostructure is constructed between LaCoO3:Er3+ and ATP when the loading amount is 10 wt%, which facilitates the separation of charge carriers and preserves the high redox potentials, leading to the enhanced photocatalytic nitrogen fixation performance. [GRAPHICS] .