Interface Engineering Of Co(Oh) 2 @Cn P-N Heterojunction for Enhanced Photocatalytic Xylose/Xylan Oxidation and Co 2  Reduction

Abstract

The construction of p-n heterojunction is considered a prominent method for promoting efficient separation/migration of photoinduced carriers, thereby enhancing photocatalytic performance. Herein, a series of nanoflower spherical Co(OH)2@CN-x p-n heterojunction photocatalysts were fabricated using a simplified one-step hydrothermal strategy. Notably, Co(OH)2@CN-2 exhibited optimal performance, showcasing a CO evolution rate of 46.2 μmol g-1 h-1 and a xylonic acid yield of 69.9%. These values are 14.7/3.7 and 2.8/2.4 times higher than those of pristine CN and Co(OH)2, respectively. Additionally, Co(OH)2@CN-2 demonstrated excellent recyclability and chemical stability. Comparative experiments, coupled with 13CO2-labelling testing, confirmed the carbon sources of the obtained CO (72.3% from CO2 reduction and 27.7% from xylose oxidation). The charge transfer mechanism in Co(OH)2@CN-x p-n heterojunctions was systematically elucidated using in-situ X-ray photoelectron spectroscopy and density functional theory calculations. This work presents a practical approach for constructing p-n heterojunction photocatalysts to enhance photocatalytic biomass oxidation coupled with CO2 reduction.

Keywords: Keywords: Biomass conversion, Carbon nitride, CO2 reduction, Photocatalysis, p-n heterojunction