Defective nano-silica loaded polymeric carbon nitride for visible light driven CO2 reduction and dye degradation

A hybrid composite of polymeric carbon nitride (PCN) and defective nano-silica (n-SiOx) photocatalyst has been synthesized, exhibiting a high surface area, improved light response, and reduced charge recombination. The synergistic formation of PCN-n-SiOx interface facilitated photoinduced charge transfer from PCN to n-SiOx, resulting in suppressed carrier recombination. The resultant hybrid PCN-n-SiOx sample demonstrated a three-fold photocatalytic reduction of CO2 into methanol and formic acid. Furthermore, photoelectrocatalytic CO2 reduction selectively yielded 283.0 μmol L−1 of formic acid, a five-fold increment compared to bare PCN (57.0 μmol L−1). These findings hold promise for the development of PCN-based hybrid composites for solar-powered applications. [Display omitted] •A strong interfacial contact of carbon nitride and defective nano-silica is realized by wet-chemical and thermolysis.•Formation of PCN-n-SiOx interface suppressed the charge carrier recombination of PCN.•Experimental and theoretical studies suggest built-in-electric field drive the charge migration from PCN to n-SiOx.•PCN-n-SiOx exhibited an enhanced photocatalytic reduction of CO2 to CH3OH and HCOOH.•Photoelectrochemical CO2 reduction over PCN-n-SiOx shown high selectivity towards HCOOH production.