Waste carbon-based toner protection layer on CsPbBr3 perovskite photoanodes for efficient and stable photoelectrochemical water oxidation.

The exceptional optical properties and good temperature stability of inorganic halide perovskites make them appealing materials for photoelectrochemical water splitting. However, their instability towards water molecules is a serious challenge. Our solution to this issue is to use waste carbon-based toner from cartridge printers to protect CsPbBr 3 -based photoanodes in aqueous electrolytes in an environmentally friendly, cost-effective, and efficient way. Waste carbon toner: graphite (WCTG) protective layer is a novel approach that we present here to recycle these environmentally harmful pollutants. Through adjustment of WCTG ratios, we discovered that the CsPbBr 3 photoanodes' photocurrent densities for water oxidation achieved 3.6 and 4.6 mA cm−2 at 1.23 vs reversible hydrogen electrode at pH 7 and pH 12, respectively. After 5 h, the most stable electrodes still maintained their photocurrent density, a critical step towards the circular economy of waste toners and the use of inorganic halide perovskites for solar water splitting. [Display omitted] • The photoanode device is prepared using the CsPbBr 3 perovskite structure as a light absorber. • Waste carbon-based toner was used on CsPbBr 3 perovskite photoanodes as a protective layer against water molecules. • The PEC water oxidation performance of the CsPbBr 3 photoanodes strikingly improves with increasing graphite. • Increasing the amount of waste carbon-based toner increases the stability of CsPbBr 3 photoanodes in aqueous electrolytes. [ABSTRACT FROM AUTHOR]