Directional Charge Transfer in V–P–Ni 1D Chain for CO ₂ Photoreduction and Mustard-Gas Simulant Detoxification

In heterogeneous photocatalysis, promoting the directed transfer of photogenerated charge carriers is critical for suppressing charge recombination and enhancing photocatalytic efficiency. Herein, the organic ligand-modified phosphovanadate [(C8N3H7)2(HPO4)(VO2)2•1.5H2O] was synthesized and denoted as VP-0D. Subsequently, transition metals were introduced during the synthesis process, successfully obtaining a coordination polymer based on a bimetallic phosphate, namely, [(C8N3H7)2Ni(PO4)VO2] (VPNi-1D). The one-dimensional phosphorus-containing inorganic chain structure of VPNi-1D facilitates rapid and directional transfer of photogenerated electrons, which contributes to its superior photocatalytic activity in CO2 reduction compared to VP-0D. During the 6-h irradiation process, the rate of CO production reached an astonishing 12399 μmol·g–1·h–1, with 93.6% selectivity. After five cycles, its activity remained above 95%. Additionally, the exposed V–O bonds of the VPNi-1D endow it with outstanding oxidative activity, enabling the chemical warfare agent simulant 2-chloroethyl ethyl sulfide (CEES) to be completely transformed into harmless 2-chloroethyl ethyl sulfoxide (CEESO) in 15 min at room temperature.