Pt-decorated ZnMn2O4 nanorods for effective photocatalytic reduction of CO2 into methanol under visible light

Abstract

The emergence of CO2 photoconversion into liquid fuels becomes a sustainable and ecological way to overcome future energy problems. Accordingly, a simple preparation of visible-light ZnMn2O4 (ZMO) nanorod harvesters is presented. These ZMO nanorods are decorated with small amount of Pt nanoparticles (0.5–2.0 wt%) to enhance the selective photoreduction of CO2 into methanol (MeOH). Depiction of the produced samples revealed a notable advance of structure and surface properties by introducing Pt. Moreover, the visible light absorption and photocharge separation were enhanced through the deposition of Pt with a reduction of the bandgap down to 1.98 eV for the 1.5% Pt/ZMO. This optimal Pt/ZMO showed a 1906 μmol/g selective photoreduction of CO2 to MeOH within 9 h at 2.4 g L-1. The prepared photocatalyst showed sustainable recyclability after five times reuse. The enhanced photocatalytic performance of Pt/ZMO is referring to the suppression of the charge recombination and improvement of the mobility as well. This work signifies the use of less noble metal supporting spinel-structured photocatalysts for renewable generation of fuels.