Facile Synthesis of g-C3N4 Nanosheets/ZnO Nanocomposites with Enhanced Photocatalytic Activity in Reduction of Aqueous Chromium(VI) under Visible Light

Abstract

Graphitic-C3N4 nanosheets (CN)/ZnO photocatalysts (CN/ZnO) with different CN loadings were successfully prepared via a simple precipitation-calcination in the presence of exfoliated C3N4 nanosheets. Their morphology and structure were thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectra (PL). The results showed that hexagonal wurzite-phase ZnO nanoparticles were randomly distributed onto the CN nanosheets with a well-bonded interface between the two components in the CN/ZnO composites. The performance of the photocatalytic Cr(VI) reduction indicated that CN/ZnO exhibited better photocatalytic activity than pure ZnO under visible-light irradiation and the photocatalyst composite with a lower loading of CN sheets eventually displayed higher activity. The enhanced performance of CN/ZnO photocatalysts could be ascribed to the increased absorption of the visible light and the effective transfer and separation of the photogenerated charge carriers.

Significantly Enhanced Aqueous Cr(VI) Removal Performance of Bi/ZnO Nanocomposites via Synergistic Effect of Adsorption and SPR-Promoted Visible Light Photoreduction

“…As shown in Figure 3c, the ZnO nanoparticles exhibited a flocculent-like structure consisting of aggregated spherical ZnO nanoparticles with an average particle size of approximately 10 nm, which was in line with the SEM observations. The lattice fringes were measured to be 0.263 nm (Figure 3d), which was in agreement with the (002) facet of the hexagonal wurtzite ZnO phase [34]. From Figure 3e, it was observed that the Bi-ZnO-80 composite was composed of two kinds of constituent particles, one with a large diameter Bi and the other with a small ZnO.…”

“…For bare ZnO, the peaks at 31.8° (100), 34.5° (002), 36.42° (010), 47.6° (102), 56.58° (110), 63.05° (103), and 67.9° (112) were highly identical with those of the ZnO hexagonal wurtzite phase (JCPDS-NO. [34]. For the BiNPs/ZnO with different Bi contents, the characteristic diffraction peaks of ZnO were weakened with an increased content of Bi metal.…”

“…Additionally, a high recombination of photo-excited carriers also makes its real applications blocked [14,15]. [34]. For the BiNPs/ZnO with different Bi contents, the characteristic diffraction peaks of ZnO were weakened with an increased content of Bi metal.…”

Novel g‐C3N4 nanosheets/CDs/BiOCl photocatalysts with exceptional activity under visible light

“…The full spectrum of the ternary photocatalyst indicated the peaks corresponding to C 1s, O 1s, N 1s, Bi 4f, and Cl 2p, and no other characteristic peaks for other elements were detected, which approves purity of the photocatalyst (Figure A). The peaks, centered in the range of 280‐294 eV, are further deconvoluted into three different peaks centered at 284.8, 289.4, and 286.0 eV, corresponding to sp 2 (C=C), C–NH 2 group of the broad asymmetric C 1s feature of g‐C 3 N 4 nanosheets, and C–OH of CDs particles, respectively (Figure B) . The spectrum of O 1s shows three distinct prominent peal peaks at 530.3, 532.1, and 534.1 eV, which correspond to the oxygen of Bi–O, C–O–C, and C=O bonds, respectively (Figure C) .…”

Synthesis, Crystal Structure, and Selected Properties of [Au(S2CNH2)2]SCN: A Precursor for Gold Macro‐Needles Consisting of Gold Nanoparticles Glued by Graphitic Carbon Nitride

“…Since this first report, many investigations and characterizations have been published with differing XPS results. [77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93] Selected data are summarized in Ta ble S4 (Supporting Information), giving the binding energies for the C1sa nd N1ss ignals. Intriguingly, in most spectra,t he signal of C1sa ta round2 88 eV dominates the C1sr egion, but there are also spectra in which this peak exhibits the lowest intensity.T he most intense N1ss ignal ranges from 398.0 to 400.06eV ( Table S4).…”