Monochromatic light-enhanced photocatalytic CO2 reduction based on exciton properties of two-dimensional lead halide perovskites. Issue 20 (13th May 2022)

• Record Type: Journal Article
• Authors: Xu, Shengqi; Yang, Lu; Wei, Yixuan; Jia, Yiming; Hu, Meiqi; Bai, Lianxia; Zhang, Junzheng; Li, Xinxin; Wei, Shuo; Lu, Jun
• Is Part Of: Dalton transactions. Volume 51:Issue 20(2022)
• Page Start: 8036
• Page End: 8045
• Publication Date: 2022-05-13
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2dt00972b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A series of 2D layered perovskites were used for photocatalytic CO2 reduction with a CO/CH4 yield of 158.69/6.9 μmol g −1 h −1 . The monochromatic light matching their exciton absorption enhanced the yield by 1.27 times, compared with the full spectrum. Abstract : Converting CO2 into valuable solar fuels through photocatalysis has been considered a green and sustainable technology that is promising for alleviating global warming and providing energy in an environmentally friendly manner. However, traditional photocatalysts generally suffer from low surface-reactive reaction sites, inefficient light harvesting and rapid recombination of electron–hole pairs. Lead halide perovskite materials have been considered ideal semiconductor photocatalysts for photocatalytic CO2 reduction due to their tunable band gaps, strong light absorption, and low cost. Herein, a series of L2 Cs n −1 Pb n X3 n +1 (L = ba, ha, oa; X = Cl, Br, I; n = 1, 2) 2D layered perovskites were synthesized by a facile solvothermal method. The effects of alkyl amine chain length, halogen atoms and inorganic layer number on their properties were studied. More importantly, these 2D materials were used as photocatalysts for CO2 reduction without any sacrificial agents. These 2D perovskites exhibited markedly increased performance in comparison with 3D bulk materials, benefitting from the larger surface-area-to-volume ratio and faster and more efficient exciton dissociation, which achieved the highest CO yield of 158.69 μmol g −1 h −1 and CH4 yield of 6.9 μmol g −1 h −1 through the design of the photocatalytic system. In addition, the influence of light source conditions on photocatalysis was studied systematically, including light source intensity and wavelength. The experimental results indicated that an appropriate solvent, high light intensity and monochromatic light source matching the wavelength of exciton absorption can effectively improve the photocatalytic efficiency.