Cellulose derived nitrogen and phosphorus co-doped carbon-based catalysts for catalytic reduction of p-nitrophenol.

The cellulose, which is one of the most abundant solid by-products of agriculture and forestry industry, has been successfully tested for the synthesis of nitrogen and phosphorus co-doped carbon-based metal-free catalysts (NPC) via freeze-drying the mixture of cellulose crystallite and ammonium phosphate, followed by annealing of the hydrogel under nitrogen atmosphere at 800 °C for 2 h. Different techniques including TEM, SEM, FTIR and XPS spectroscopy have been applied to characterize the as-prepared NPC, which presents flake-like morphology with N and P doping levels of 4.3 atom% and 10.66 atom%, respectively. The NPC exhibits excellent catalytic activity for the reduction of p-nitrophenol (p-NP). The turnover frequency (TOF) of the reduction of p-NP is as high as 2 × 10 mmol·mg·min and the apparent kinetic rate constant was calculated as 0.0394 min at room temperature. The catalytic mechanism is proposed by combining the density functional theory calculation and analysis of the experimental results. These findings open up new possibilities of valorization for cellulose-based by-product and treatment of p-NP-based wastewater.