Construction of Highly Efficient 3D/2D MnO₂/g-C₃N₄ Nanocomposite in the Epoxidation of Styrene with TBHP

Abstract

MnO2/g-C3N4 nanocomposites were facilely synthesized by calcining the mixture of bulk g-C3N4 and MnO2 precursors. The effects of the morphology of MnO2 precursors and the mass ratio of MnO2 to g-C3N4 on the micromorphology, chemical compositions, and catalytic properties of MnO2 NP/g-C3N4 nanocomposites were studied. It was found that the 3D polyhedral morphology and multiphase polycrystalline structure of MnO2 were propitious to generate the strong interaction between MnO2 and g-C3N4, which led to the enhanced concentrations of surface low-valence Mn species, oxygen vacancies, and graphitic N species. Meanwhile, when the mass ratio of MnO2 NP to g-C3N4 was 8/100, the interface of 8MnO2NP/UCN possessed the optimum synergistic effect of MnO2 NP and g-C3N4, contributing to the superior catalytic performance of 8MnO2NP/UCN with much higher yield of styrene oxide compared to other counterparts.

Mg−O‐Bridged Polypyrrole/g‐C3N4 Nanocomposites as Efficient Visible‐Light Catalysts for Hydrogen Evolution

“…The XRD patterns (Figure S6 FT-IR spectra were also recorded, as shown in Figure S8 (Supporting Information). Compared with g-C 3 N 4 [29,50] and NPPy, [51,52] 1NP-CN and 1NP-3Mg-CNs how the typical CÀH stretching vibration peak of NPPy at about1 033 cm À1 ,a sw ell as the characteristic peaks of g-C 3 N 4 (the OÀHp eak at 3177 cm À1 ,the peaks in the region of 1250-1650 cm À1 attributed to the stretching vibration of CÀNh eterocycles, and the peak at around 808 cm À1 corresponding to the bending vibration of hepazine rings). This confirms the successful fabrication of the NPPy/g-C 3 N 4 nanocomposites.M ore notably,f or 1NP-3Mg-CN,two clear peaks are observed at 647 and 493 cm À1 ,attributedt ot he deformation vibrations of MgÀOa nd OÀMgÀO, respectively, [53] confirming that MgÀOb ridges are indeed introduced into the NPPy/g-C 3 N 4 nanocomposites.…”

Fabrication of hollow flower-like magnetic Fe3O4/C/MnO2/C3N4 composite with enhanced photocatalytic activity

“…The layered structure of δ-MnO 2 is formed by the MnO 6 octahedral layer with shared edges, and there are some cations and H 2 O molecules between the layers to maintain the charge balance 33 . δ-MnO 2 has been widely used as a catalyst to purify the environment [34][35][36] . However, while the narrow band gap increases the usage of visible light, it is also accompanied by the rapid recombination of photo-generated electrons and holes.…”

MnO2‐Based Materials for Environmental Applications

“…In recent years, the combination of MnO 2 and graphitic carbon nitride (g‐C 3 N 4 ), which is a multifunctional material used in a wide range of photocatalytic applications and other energy conversion processes, has attracted growing interest. [ 255–261 ] Xia et al. [ 258 ] used a wet chemical method to grow MnO 2 nanoflakes on the surface of a g‐C 3 N 4 nanolayer and constructed a 2D/2D g‐C 3 N 4 /MnO 2 Z‐scheme photocatalyst.…”