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

Abstract

Lead halide perovskites driven photocatalytic CO2 reduction reaction (CO2RR) is restricted by H2O proton source due to the poor water-resistance of perovskites and difficult dissociation of H2O molecules. In this paper, a novel solid-state proton donor of amino acid modified melamine foam (Ami-MF) is developed, which could improve CO2RR of CsPbBr3/Bi2WO6 S-scheme heterojunction. On the one hand, amino acid molecules possess abundant –COOH and –NH2 groups, which are broken easily by catalyst oxidation compared with H2O, supplying sufficient protons for CO2RR. Product yield of Glu-MF/CsPbBr3/Bi2WO6 reaches 112.81 μmol/g/h, which is 3.8 times higher than that (29.83 μmol/g/h) of H2O-MF/CsPbBr3/Bi2WO6. 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 exhibits the best CO2RR 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 is about 46.2 times higher than that (2.44 μmol/g/h) of powdery Glu/CsPbBr3/Bi2WO6, which ascribes to the efficient gas–solid CO2RR system induced by the three-dimensionality and porosity of MF. This study develops an efficient solid proton donor to enhance perovskites driven CO2RR.