Metal-free phosphorus and boron-doped graphitic carbon nitride/zeolite hetero-linked particles for highly efficient green hydrogen production in methanol.

Herein, the development of phosphorus and boron-doped graphitic carbon nitride/zeolite (P- and B-doped g-C3N4-zeolite) catalyst under three-step heating conditions was performed. The first step is to prepare g-C3N4 synthesis from urea at 500 °C. In the second step, the production of a B-doped zeolite-g-C3N4 catalyst by calcination of g-C3N4 and zeolite was obtained at a ratio of 1:1 with boric acid at 500 °C. In the third step, the obtained B-doped zeolite- g-C3N4 catalyst consists of the preparation of B- and P-doped g-C3N4-zeolite catalyst as a result of the hydrothermal method with phosphoric acid. Characterization studies of the obtained catalysts were carried out with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). These obtained catalysts were used as a metal-free catalyst in the production of hydrogen (H2-P) by sodium borohydride in methanol(NaBH4-MR) for the first time in the literature. The hydrogen production rate (HGR) value for P- and B-doped g-C3N4-zeolite catalysts was 6250 ml min-1 g-1.

Phosphorus and oxygen co-doped carbon particles based on almond shells with hydrothermal and microwave irradiation process for adsorption of lead (II) and cadmium (II).

In this study, the production of activated carbon based on almond shells by microwave heating with KOH activation and then the modification of activated carbon with phosphorus and oxygen as a result of hydrothermal heating with phosphoric acid were carried out to increase the Cd(II) and Pb(II) adsorption efficiency. The resulting materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric/differential thermal analyzer (TG-DTA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and nitrogen adsorption. Adsorption performance, kinetics and thermodynamics of phosphorus, and oxygen-doped activated carbons were evaluated. The results showed that the adsorption of both Cd(II) and Pb(II) on phosphorus and oxygen-doped activated carbons obeyed the Langmuir isotherm and pseudo-second-order kinetics. The adsorption capacity values (Qm) obtained from the Langmuir isotherm for Cd(II) and Pb(II) adsorption were 185.18 mg/g and 54.64 mg/g, respectively. At the same time, the adsorption mechanism of Pb(II) and Cd(II) on the respective adsorbents was evaluated. As a result of phosphorus and oxygen atoms, Lewis base sites on carbon atoms and Lewis acid sites on phosphorus atoms are likely to form on the surface. These Lewis base sites can act as important active sites in adsorption reactions, especially of positively charged Pb(II) and Cd(II) ions.