Facile fabrication of P-doped g-C3N4 particles with nitrogen vacancies for efficient dehydrogenation of sodium borohydride methanolysis

Abstract

The graphitic carbon nitride (g-C3N4) has become important in the field of environmental remediation with its metal-free and low-cost advantages. Here, for the first time in the literature, P doped graphitic carbon nitride (g-C3N4) was used in the dehydrogenation of sodium borohydride (NaBH4) methanolysis. The effects of interaction time with phosphoric acid (H3PO4), NaBH4 concentration, amount of catalyst and temperature were investigated. The best interaction time with phosphoric acid was found to be 12 h. There was a 2-fold increase in the HGR values obtained by increasing the amount of NaBH4 from 1.25% to 2.5%, while there was a less proportional increase with increasing the amount of NaBH4 from 2.5% to 5%. Depending on the increase in the amount of catalyst, there is a decrease in the completion times of this reaction. H2 production rate of NaBH4 methanolysis increases rapidly with increasing temperature. An HGR value of 8666 mL min−1 cat−1 using P doped g-C3N4 (10 mg) was found. The activation energy obtained for this metal-free catalyst was 30.29 kJ mol−1. Scanning electron microscopywith energy dispersive X-Ray analysis (SEM-EDX), X-ray photoelectron spectroscopy (XPS), Transmission electron microscope(TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) analyses were used for characterization. A possible reaction mechanism was proposed for the catalyst used in this methanolysis reaction. At the same time, repeatability experiments were carried out for the catalyst.