Solar Induced CO2 Reduction Achieved by Halide Tuning in Cesium Titanium (IV) Mixed Perovskite

Abstract

Atmospheric carbon dioxide (CO2) levels are rising dramatically owing to the unmonitored usage of fossil fuels, raising not only environmental hazards but also energy crises. Green energy that is, derived from renewable sources is the better exploitation of solar energy and hence, a promising idea for an efficient conversion of CO2 to hydrocarbon fuels (CxHyOz). Currently, the research activities in carbon-neutral technologies are focused on developing novel catalysts and designing highly effective conversion kinetics. In this context, for since past few years, zero lead all-inorganic halide perovskites have been trending as capable candidates due to their exceptional optoelectronic properties. Herein, we report on the facile synthesis of cesium titanium (IV) mixed halide perovskite ((CsTi(Brx.I1-x)3) with x value varying from 0 to 1) by tuning the bromide (Br) to iodide (I) ratio and its use for solar-induced CO2 reduction. Scanning electron micrographs revealed hierarchical morphology composed of several nanowires assembled into microspheres resembling the dandelions. In the presence of natural sunlight, pristine cesium titanium (IV) mixed halide perovskite (CsTi(Brx.I1-x)3) with x=0.5, yielded ~159 µmol/g of CO gas, ~94 µmol/g of CH4 and ~14 µmol/g of H2 under 6 h of experimental conditions. A lower conversion rate was observed in presence of artificial solar and UV light, which could be due to experimental conditions. The findings reported here are anticipated to contribute to the vast field of novel materials for solar fuel generation.