Bias-free solar NH3 production by perovskite-based photocathode coupled to valorization of glycerol
摘要
Photoelectrochemical production of ammonia (NH3) is potentially eco-friendly but suffers from a low solar-to-ammonia productivity (SAP) and requires a high additional bias for the overall NH3 production from nitrate reduction and water oxidation. Here we applied a high-performance triple-cation lead halide (Cs0.05(FA0.83MA0.17)0.95Pb(Br0.17I0.83)3) perovskite photocathode with integrated electrocatalyst to achieve high SAP and coupled glycerol oxidation instead of water oxidation for bias-free NH3 production. Stable, selective NH3 production and glycerol oxidation were achieved by respectively loading Ru and Pt electrocatalysts on conductive and stable titanate nanosheet supports, instead of corrodible carbon-based supports. Our photoelectrochemical NH3 production system coupled to glycerol oxidation demonstrated a photocurrent density of 21.2 ± 0.7 mA cm−2 and SAP of 1,744.9 ± 20.6 µgNH3 cm−2 h−1 with 99.5 ± 0.8% Faradaic efficiency without applying any additional bias. Simultaneously, glycerol was selectively oxidized to glyceric acid as a major value-added product.