Lan Ding,Fenghua Bai,Burenbayaer Borjigin,Yuning Li,Huiqin Li,Xiaojing Wang
Solar-energy-driven CO 2 conversion into valuable chemical fuels holds great renewable potential. However, most photocatalysts' weak CO 2 adsorption limits more artificial photosynthesis for further utilization. Herein, we present an in situ assembling approach to produce stable Cs 2 AgBiBr 6 /Ce-UiO-66-H composite, in which a tight contact interface between the two participated components was constructed. Benefiting from the photocatalytic properties and high adsorption capacity for CO 2 , the optimized 20Cs 2 AgBiBr 6 /Ce-UiO-66-H adsorption-photocatalyst exhibits outstanding performance for reductive CO 2 deoxygenation with considerable CO generation rate (309.01 μmol g −1 h −1 ) under simulated solar light irradiation with 300 W Xe lamp, which is about 2.1 and 2.7 times than that of pure Cs 2 AgBiBr 6 and Ce-UiO-66-H, respectively. The excellent catalytic conversion of CO 2 is ascribed to the effective solar harvest and quickly photo-excited carriers’ separation in such assembled architecture. Importantly, due to the in-situ synthesis, Cs 2 AgBiBr 6 QDs are intercalated in the Ce-UiO-66-H frameworks and it could lead to improved stability and induce abundant oxygen vacancies in Cs 2 AgBiBr 6 /Ce-UiO-66-H, which can maintain unchangeable CO 2 conversion rate under wet air with consecutive ten hours of the recycling test. In this work, the combining metal–organic frameworks and lead-free halide perovskite provide great potential for artificial photocatalytic CO 2 -to-CO conversion under a mild gas–solid reaction condition via utilizing solar energy.
Quaternary Cs2AgBiBr6 perovskites have been considered as a potential candidate to simultaneously resolve the lead toxicity and instability issues of unprecedented organic–inorganic hybrid halide perovskites. Unfortunately, the photovoltaic efficiency is still lower owing to the great challenge to make high-quality Cs2AgBiBr6 film with fewer defects. Herein, we demonstrate alkali metal ions including Li+, Na+, K+, and Rb+ as mediators to regulate the crystal lattice and film quality of Cs2AgBiBr6 perovskites. A less-pinhole perovskite film is obtained by precisely controlling the doping dosage and element species, significantly reducing the defects. When assembled into a hole-transporting material-free, carbon-electrode perovskite solar cell, a significantly enhanced efficiency of 2.57% compared to the undoped device with 1.77% efficiency has been achieved owing to the suppressed shunt current loss. Additionally, this device displays superior tolerance under high-temperature and air conditions without encapsulation, providing new opportunities to promote the future development of lead-free Cs2AgBiBr6 perovskites in the photoelectric field.