Synthesis of Transition Metal‐Modified Carbon Nitride Polymers for Selective Hydrocarbon Oxidation

Abstract

Modification of graphitic carbon nitride (g-C(3)N(4)) photocatalyst with transition metals was achieved with a simple soft-chemical approach using dicyandiamide monomer and metal chloride as precursors, in combination with a thermal-induced polycondensation at 600 °C under nitrogen atmosphere. The resultant organic-inorganic hybrid materials were thoroughly characterized by a variety of techniques, including X-ray diffraction (XRD), UV/Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), N(2)-sorption, transmission electron microscopy (TEM), photoluminescence (PL), and FTIR. Benzene hydroxylation and styrene epoxidation reactions were employed to evaluate the catalytic/photocatalytic activity of the synthesized g-C(3)N(4)-based catalysts. Results showed that Fe- and Cu-modified g-C(3)N(4) were active for the hydroxylation of benzene to phenol using H(2)O(2) under mild conditions. It was also found that g-C(3)N(4) could promote the catalytic epoxidation of styrene using molecular oxygen as the primary oxidant; after modification with Co and Fe, the catalytic performance for styrene epoxidation with O(2) could be significantly improved, especially when coupled with visible-light irradiation.

Enhanced photocatalytic H2 evolution over CdS/Au/g-C3N4 composite photocatalyst under visible-light irradiation

“…Therefore, g-C 3 N 4 could be a remarkable candidate for building Z-scheme photocatalytic systems. Although a number of attempts have been made to enhance the photocatalytic activity of g-C 3 N 4 , such as preparing nanoscale porous structures, 27 chemical doping with nonmetal elements, 28,29 depositing with metal atoms, 30,31 and constructing heterostructures, [32][33][34][35] the g-C 3 N 4 based Z-scheme photocatalytic systems are still very limited. Herein, a novel ternary composite of CdS/Au/g-C 3 N 4 was successfully synthesized, in which the Au nanoparticles were coated with the CdS particles and deposited on the g-C 3 N 4 surface.…”

The Preparation of Cu-g-C3N4/AC Catalyst for Acetylene Hydrochlorination

“…The peak at 12.9 • is the (100) characteristic peak for g-C 3 N 4 , which is typical of highly oriented melons [11]. The characteristic peak for the copper-modified g-C 3 N 4 is slightly wider and weaker than that of pure g-C 3 N 4 [12]. Notably, the XRD spectra of Cu-g-C 3 N 4 /AC do not show the characteristic peak related to the copper element, such as that of copper or copper oxide.…”

“…The catalysts were prepared as reported previously [12]. First, at 80 • C, dicyandiamide was mixed with deionized water, stirred for 30 min.…”

Enhanced visible light photocatalytic H2 production activity of g-C3N4 via carbon fiber

“…However, the photocatalytic activity of the pure g-C 3 N 4 is often limited because of its fast recombination rate of photoinduced electron-hole pairs and low specific surface area [27,30,31]. To optimize the photocatalytic performance of g-C 3 N 4 , various approaches have been applied, including structural improvement [27,[32][33][34][35][36][37], introducing heteroatoms (metal or nonmetal) to tune its electronic band structure [27,[38][39][40][41][42] and coupling with other components (metal oxides, monomer, carbon based materials et al) [22,27,[43][44][45][46][47][48][49][50][51] to efficiently enhance its photogenerated charge separation.…”