Natural polymer/wide-bandgap inorganic hybrids for visible-light-driven CO₂ photoreduction: Unraveling the multiple effects of interfacial chemical bonding

Biomass-derived nanocomposites represent a developing class of multifunctional materials with biomimetic implications. Here, cellulose nanocrystal interfacially bonded Bi2O2CO3 hybrids (CNC#BOC) were fabricated via a hydrothermal approach for visible-light CO2 photoreduction. The as-synthesized CNC#BOC demonstrated superb photocatalytic activity with a CO production rate of 15.22 mu mol g(-1) h(-1), a selectivity of similar to 97 %, and excellent cycling stability. Theoretical calculations and experimental studies indicated the existence of covalent bonds between the BOC and CNC, resulting in LMCT photosensitization, a narrowed bandgap energy, plentiful and stable OVs, high reactants affinity, fast electron transfer channels, and facile formation of *COOH intermediate. This study introduces a novel covalent bonding tactic for developing natural polymer-based catalysts for selective CO2 photoreduction, which is expected to broaden the applications of environmentally friendly biomass composites.