A Crystalline Carbon Nitride Based Near‐Infrared Active Photocatalyst

Abstract

Efficient utilization of near-infrared (NIR) light that takes a primary percentage of the solar spectrum is of great significance for practical applications of photocatalysis. However, development of singular NIR-based photocatalysts still remains a grand challenge. Herein, a NIR-based crystalline carbon nitride photocatalyst is proposed by using a molten-salt assisted protocol with carbohydrazide as the oxygen-containing precursor. Different from the doping strategy that always leads to structural damage and crystallinity decrease, structural oxygen arising from the special precursor itself is introduced into the framework of C 3 N 4 with highly crystalline structure formed. The n→π* excitation is therefore activated with the absorption edge extended remarkably to 1400 nm. Theoretical calculations also reveal that the local internal electric field is simultaneously generated for promoting the charge separation/migration kinetics. Benefiting from structural oxygen incorporation and crystalline structure formation, the synthesized material shows a significantly enhanced visible-light (λ > 420 nm) hydrogen production reactivity compared with the benchmark carbon nitride, and more importantly an active NIR hydrogen generation (λ > 700 nm) and long-wavelength overall water splitting (λ = 600 nm) capability that is rarely reported for singular photocatalysts. This study showcases an illustration of promising singular NIR photocatalysts for efficient solar fuel production.

Efficient Activation of Peroxymonosulfate by V-Doped Graphitic Carbon Nitride for Organic Contamination Remediation

“…TEM was further utilized to reveal the detailed structure of V-doped g-C 3 N 4 . The layer sheet morphology with some porous structure is clearly observed in V-g-C 3 N 4 -0.5 (Figure 1e), which may be generated by the release of gas during the thermal decomposition of precursors [34][35][36]. The HRTEM image (Figure 1f) reveals that no crystalline phases are seen on the surface of g-C 3 N 4 , which is consistent with the results of SEM [31,37].…”

Fabrication of porous and visible light active ZnO nanorods and ZnO@TiO2core–shell photocatalysts for self-cleaning applications

“…The second deconvoluted peak at lower binding energy explicitly describes the number of oxygen ions (cations) present in the oxygen-deficient region, which further determines the density of oxygen vacancies. 7,53–56…”

Photocatalytic Disulfide Bond Coupling by Surface-Reduced Manganese Oxide for Controlled Polysulfide-Based Polymer Synthesis

“…Significantly, the E g value shows an evident decline in the case of an oxygen vacancy, which can be calculated to be 0.730 eV. As is known, catalyst materials with a small E g value generally represent excellent electronic and optical properties, thus leading to enhanced carrier transfer and photocatalytic activities. , Given that the S–S coupling of the terminal SH groups of liquid polysulfide rubber is the critical step during the vulcanization process, the S–S coupling reaction barriers over different MnO 2 structures under visible-light irradiation were also evaluated (Figure c). As expected, the oxygen vacancy in MnO 2 can remarkably decrease the S–S coupling barrier, thus confirming that the oxygen vacancy plays a pivotal role in the formation of a polysulfide sealant. , As for the oxidation of the SH group in the absence of light, Gibbs free-energies at various temperatures were calculated.…”