Fe-Doped g-C3N4: High-Performance Photocatalysts in Rhodamine B Decomposition

Abstract

Herein, Fe-doped C3N4 high-performance photocatalysts, synthesized by a facile and cost effective heat stirring method, were investigated systematically using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area measurement, X-ray photoelectron (XPS), UV–Vis diffusion reflectance (DRS) and photoluminescence (PL) spectroscopy. The results showed that Fe ions incorporated into a g-C3N4 nanosheet in both +3 and +2 oxidation states and in interstitial configuration. Absorption edge shifted slightly toward the red light along with an increase of absorbance in the wavelength range of 430–570 nm. Specific surface area increased with the incorporation of Fe into g-C3N4 lattice, reaching the highest value at the sample doped with 7 mol% Fe (FeCN7). A sharp decrease in PL intensity with increasing Fe content is an indirect evidence showing that electron-hole pair recombination rate decreased. Interestingly, Fe-doped g-C3N4 nanosheets present a superior photocatalytic activity compared to pure g-C3N4 in decomposing RhB solution. FeCN7 sample exhibits the highest photocatalytic efficiency, decomposing almost completely RhB 10 ppm solution after 30 min of xenon lamp illumination with a reaction rate approximately ten times greater than that of pure g-C3N4 nanosheet. This is in an agreement with the BET measurement and photoluminescence result which shows that FeCN7 possesses the largest specific surface area and low electron-hole recombination rate. The mechanism of photocatalytic enhancement is mainly explained through the charge transfer processes related to Fe2+/Fe3+ impurity in g-C3N4 crystal lattice.

The Influence of Metal-Doped Graphitic Carbon Nitride on Photocatalytic Conversion of Acetic Acid to Carbon Dioxide

“…The band-gap energies of CN and CuZn_CN materials were found to be slightly higher than 3.0 eV, which is in line with the results obtained by Dante et al (2021 ) and Katsumata et al (2019 ) for metal-doped CN. The extended absorption spectra of metal-doped CN materials shifted into the visible range (400–50 nm), as seen in other reports ( Dante et al, 2021 ; Liu et al, 2017 ; Nguyen Van et al, 2020 ). On the other hand, the absorption characteristics of CuZn_CN were found to be similar to pristine CN.…”

“…Results indicate that PL spectral intensities for metal(s)-doped CN spectra are significantly lower than that of pristine CN. A possible reason for this is trapping of photogenerated electrons by metal-doping sites, which leads to slower electron-hole recombination rates ( Nguyen Van et al, 2020 ; Cui et al, 2021 ). Nevertheless, XPS spectra ( Supplementary Figure S1 ) suggested the very small amount of metal incorporated on the CN surface, insufficient to be detected by the surface characterization technique.…”

Constructing LaxCoyO3 Perovskite Anchored 3D g-C3N4 Hollow Tube Heterojunction with Proficient Interface Charge Separation for Stimulating Photocatalytic H2 Production

“…The significant difference in crystal size of LaCoO 3 precursor, i.e., 1.38 nm, and pure LaCoO 3 phase, i.e., 37.10 nm, is obviously due to the higher calcination temperature to obtain the pure LaCoO 3 phase, which led to the formation of poly crystals having large particles sizes . The crystal cell lattice of P-g-C 3 N 4 , i.e., a = b = 4.831 Å, c = 6572 Å shows the hexagonal crystal structure, while the physical parameters of pure LaCoO 3 were a = 5.442 Å, b = 5.442 Å, c = 13.097 Å, and V = 387.872 Å 3 , approving rhombohedral distorted crystalline perovskite structure according to JCPDS 25-1060. Also, after heterojunction formation of LaCoO 3 /P-g-C 3 N 4 , there was an obvious reduction in crystal size of LaCoO 3 from 37.10 to 33.2 nm, which is based on the interaction of LaCoO 3 with P-g-C 3 N 4 for the heterojunction formation.…”

Photocatalytic activation and utilization of CO2 for N-formylation of amines promoted by a zinc(ii) phthalocyanine grafted on g-carbon nitride hybrid

“…CN shows direction transitions, so the corresponding value of n = 1. 35 The band gap of the different synthesized materials calculated using Tauc plot (Fig. S3†) was found to be in the following order: CN > ZPCN-2.5 > ZPCN-5 > ZPCN-7.5 > ZPCN-10 > ZP (ZP).…”