Facile fabrication of a mpg-C₃N₄/TiO₂heterojunction photocatalyst with enhanced visible light photoactivity toward organic pollutant degradation

Abstract

A facile hard template approach has been developed to prepare mpg-C 3 N 4 /TiO 2 composites using SiO 2 nanoparticles as hard template and cyanamide as precursor. The samples were well characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). The results demonstrated that TiO 2 nanoparticles sized 5-10 nm were distributed on the surface of mpg-C 3 N 4 to form the mpg-C 3 N 4 /TiO 2 heterojunction photocatalyst. In this way, the mpg-C 3 N 4 /TiO 2 heterojunction catalysts have a porous structure and large surface areas, which increase the contact area of pollutants. Rhodamine B (RhB) was carried out as a representative organic pollutant to evaluate the photocatalytic activity of samples under visible light irradiation. The results showed that the as-prepared mpg-C 3 N 4 /TiO 2 heterojunction catalysts significantly enhanced the visible photocatalytic activity compared to pure mpg-C 3 N 4 and the degradation rate was 1.6 times higher than that of pure mpg-C 3 N 4 . The increased photocatalytic activity of mpg-C 3 N 4 /TiO 2 heterojunction can be attributed to the formation of the heterojunction between mpg-C 3 N 4 and TiO 2 , which suppresses the recombination of photoinduced electron-hole pairs. Furthermore, based on systematic characterizations and discussions, a possible photocatalytic mechanism for the excellent

Synthesis of Hierarchical TiO2–C3N4 Hybrid Microspheres with Enhanced Photocatalytic and Photovoltaic Activities by Maximizing the Synergistic Effect

“…These results suggest that the enhanced photocatalytic activity of TiO 2 –C 3 N 4 (ST) could be attributed to the synergistic effect between TiO 2 and C 3 N 4 , instead of a possible contribution from the improved activities of the individual TiO 2 and C 3 N 4 synthesized by means of the ST method. The excellent photocatalytic activity of TiO 2 –C 3 N 4 (ST) is even superior to the reported TiO 2 –C 3 N 4 photocatalysts and is comparable to most reported state‐of‐the‐art highly active photocatalysts (Table ) . Only amorphous carbon‐coated TiO 2 displayed higher photocatalytic activity than our TiO 2 –C 3 N 4 (ST) microspheres; however, this photocatalyst suffered from complex preparation methods .…”

“…Thee xcellent photocatalytic activity of TiO 2 -C 3 N 4 (ST) is even superior to the reported TiO 2 -C 3 N 4 photocatalystsa nd is comparable to mostr eporteds tate-of-the-art highly active photocatalysts ( Table 1). [11][12][13][14][28][29][30][31][32][33][34][35][36][37][38][39] Only amorphous carboncoated TiO 2 displayedh igherp hotocatalytic activity than our TiO 2 -C 3 N 4 (ST) microspheres;h owever,t his photocatalyst suffered from complex preparation methods. [35] In addition, we studied the effect of the amount of C 3 N 4 on the photocatalytic activity of the TiO 2 -C 3 N 4 (ST) hybrid, as shown in Figure S3.…”

Synthesis of nanoporous carbon nitride using calcium carbonate as templates with enhanced visible-light photocatalytic activity

“…Therefore, many strategies have been taken to modify g-C 3 N 4 such as doping metal-nometal ions [12][13][14][15], combining with other semiconductors [18][19][20][21][22], constructing g-C 3 N 4 -based Z-scheme [23][24][25][26], fabricating the π conjugated structure to reduce the position of the valence band [25,26], and designing an appropriate textural porosity [29][30][31][32][33][34][35]. The fabrication of porous g-C 3 N 4 with high surface area and tunable pore diameter is particular interest because a larger surface area of photocatalyst can be favorable for the photoactivity by providing more contact chances between the photocatalysts and substances.…”

Synergy of Iron Doping and Cyano Groups for Enhanced Photocatalytic Hydrogen Production over C3N4

“…Current research mainly includes two kinds of element doping, namely non‐metal doping and metal doping. So far, O, [2] C, [3] P, [4] S, [5] B, [6] I, [7] F [8] doping and their co‐doping have been widely reported [9] . Doping of metal elements such as Fe, Cu, Zn, and Ni has also been used to enhance the charge carriers transfer rate and lifetime, thereby improving the photocatalytic activity of C 3 N 4 [10,11] .…”