An effective approach for tuning catalytic activity of C3N nanosheets: Chemical-doping with the Si atom

Theoretical study of metal-free catalytic for catalyzing CO-oxidation with a synergistic effect on P and N co-doped graphene

P and N co-doped graphene (PN_xC_y-G with x = 1, 2, 3 and y = 0, 1, 2) is designed to enhance graphene reactivity with a synergistic effect of the P and N atoms for the CO oxidation reaction, focusing on the influence of the N dopant concentration on graphene. The calculated results indicate that increasing two or three coordinated N to P can facilitate charge transfer from the surface onto O₂ molecules. However, the adsorbed O₂ molecule breaks apart on PN₃-G surface, affecting CO oxidation performance. Furthermore, PN₂C₁-G exhibits excellent catalytic activity towards the oxidation of CO via the ER mechanism, which catalyzes CO oxidation with the rate-determining step of only 0.26 eV for the first and 0.25 eV for the second oxidation at 0 K. Additionally, the catalytic oxidation of PN₂C₁-G via Eley–Rideal mechanism prefers to occur at room temperature (298.15 K), with a rate-determining step of 0.77 eV. The reaction rates at 298.15 K is calculated to be 5.36 × 10¹⁶ mol s^–1. The rate constants are obtained according to harmonic transition state theory, which could be supportive for catalytic oxidation of CO on the experiment.

Theoretical insights into oxygen reduction reaction catalyzed by phosphorus-doped divacancy C3N nanosheet

The catalytic reduction of O₂ molecule into H₂O is investigated over a P-doped divacancy C₃N nanosheet (P-Dv-C₃N) by using density functional theory calculations. A negative formation energy is calculated for P-Dv-C₃N, suggesting that the introduction of a P atom into divacancy defective C₃N would be thermodynamically favorable. The oxygen reduction reaction (ORR) over P-Dv-C₃N would proceed via a 4e^- pathway (O₂ + 4H⁺ + 4e^-→ 2H₂O) at room temperature. The rate-determining step of the ORR on P-Dv-C₃N is O + H⁺ + e^- → OH which requires an activation energy of 1.21 eV. These results provide helpful insights into design novel metal-free catalysts to improve the kinetics of ORR in fuel cells.

Heteroatom-doped C3N as a promising metal-free catalyst for a high-efficiency carbon dioxide reduction reaction

Converting CO₂ into useful fuels and chemicals offers a promising strategy for mitigating the issues of energy crisis and global warming.

Introducing novel electronic and magnetic properties in C3N nanosheets by defect engineering and atom substitution

Using first-principles calculations the effects of topological defects, vacancies, Stone–Wales and anti-site and substitution of atoms, on the structure and electronic properties of monolayer C₃N are investigated.