Near-infrared-induced self-healing gel catalyst and its sustainable application for catalytic reduction of 4-nitrophenol

Responsive catalysts with self-healing response capabilities will have great potential in sustainable catalytic applications, effectively extending the lifespan of catalysts. Herein, a near-infrared-responsive self-repairing composite gel catalyst is presented for efficient and sustainable reduction of 4-nitrophenol (4-NP, i.e., a specific organic pollutant). Copper nanoparticles (CuNPs) serve as catalytic species, while transition metal carbide (Ti₃C₂T_x) acts as efficient electron transfer medium in the composite gel. The synergistic effect of these components significantly enhances catalytic activity of the gel (e.g., the catalytic rate constant k for 4-NP reduction reaches up to 0.6159 min⁻¹). More importantly, by leveraging the self-healing of poly(N, N-dimethylacrylamide) (PDMAA, i.e., the third component in the gel) and combining the photothermal conversion of Ti₃C₂T_x, the gel is endowed with the ability to rapidly repair itself by near-infrared light induction, thereby ensuring its sustainability in the catalytic application. This photo-induction way not only effectively repairs the damaged gel catalyst but also preserves its catalytic efficiency, making it ideal for prolonged application. This research offers novel insights into using responsive catalysts to achieve sustainable and efficient catalytic application.