Enhanced photocatalytic CO2 conversion into reusable fuels with efficient solid-state proton donors

Lead halide perovskites driven photocatalytic CO2 2 reduction reaction (CO2RR) 2 RR) is restricted by H2O 2 O proton source due to the poor water-resistance of perovskites and difficult dissociation of H2O 2 O molecules. In this paper, a novel solid-state proton donor of amino acid modified melamine foam (Ami-MF) is developed, which could improve CO2RR 2 RR of CsPbBr3/Bi2WO6 3 /Bi 2 WO 6 S-scheme heterojunction. On the one hand, amino acid molecules possess abundant -COOH and -NH2 2 groups, which are broken easily by catalyst oxidation compared with H2O, 2 O, supplying sufficient protons for CO2RR. 2 RR. Product yield of Glu-MF/CsPbBr3/Bi2WO6 3 /Bi 2 WO 6 reaches 112.81 mu mol/g/h, which is 3.8 times higher than that (29.83 mu mol/g/h) of H2O-MF/CsPbBr3/Bi2WO6. 2 O-MF/CsPbBr 3 /Bi 2 WO 6 . Moreover, glutamic acid (Glu), cysteine (Cys), arginine (Arg) as typical acidic, neutral and basic amino acids are selected to explore proton supply from different amino acids. Glu-MF/CsPbBr3/Bi2WO6 3 /Bi 2 WO 6 exhibits the best CO2RR 2 RR than other two Ami-MF, ascribing to the dicarboxylic structure of Glu. On the other hand, MF is an integral part in solid-state proton donor. Product yield of Glu-MF/CsPbBr3/Bi2WO6 3 /Bi 2 WO 6 is about 46.2 times higher than that (2.44 mu mol/g/h) of powdery Glu/CsPbBr3/ 3 / Bi2WO6, 2 WO 6 , which ascribes to the efficient gas-solid CO2RR 2 RR system induced by the three-dimensionality and porosity of MF. This study develops an efficient solid proton donor to enhance perovskites driven CO2RR. 2 RR.