Photocatalytic degradation of tetracycline hydrochloride with g-C3N4/Ag/AgBr composites

Abstract

Graphite carbon nitride (g-C3N4), as a polymer semiconductor photocatalyst, is widely used in the treatment of photocatalytic environmental pollution. In this work, a Z-scheme g-C3N4/Ag/AgBr heterojunction photocatalyst was prepared based on the preparation of a g-C3N4-based heterojunction via in-situ loading through photoreduction method. The g-C3N4/Ag/AgBr composite showed an excellent photocatalytic performance in the degradation of tetracycline hydrochloride pollutants. Among the prepared samples, g-C3N4/Ag/AgBr-8% showed the best photocatalytic ability for the degradation of tetracycline hydrochloride, whose photocatalytic degradation kinetic constant was 0.02764 min−1, which was 9.8 times that of g-C3N4, 2.4 times that of AgBr, and 1.9 times that of Ag/AgBr. In the photocatalytic process, •O2– and •OH are main active oxygen species involved in the degradation of organic pollutants. The photocatalytic mechanism of g-C3N4/Ag/AgBr is mainly through the formation of Z-scheme heterojunctions, which not only effectively improves the separation efficiency of photogenerated electron-hole pairs, but also maintains the oxidation and reduction capability of AgBr and g-C3N4, respectively.

Ag/AgBr-oxygen enriched g-C3N4 for efficient photocatalytic degradation of trimethylamine

“…20,33 The binding energies of Br 3d 5/2 and Br 3d 3/2 were 67.5 and 68.5 eV, indicating that the negative valence of Br existed in the system. 21,23,25,31,32…”

“…Ag was used as an electron storage pool, and a ternary heterojunction was constructed, which enhanced the separation of the photogenerated electron-hole pairs and improved the photocatalytic degradation of TMA. 25 Using ESR to study the effective photogenerated carriers produced by photoexcited samples more intuitively. Fig.…”

Photocatalytic Hydrogen Production and Tetracycline Degradation Using ZnIn2S4 Quantum Dots Modified g-C3N4 Composites

“…Wang et al first reported the characteristics of CN for hydrogen production from water [ 10 ]. Since then, it has set off a research boom in the field of photocatalysis [ 11 , 12 , 13 , 14 , 15 ]. In the research of photocatalytic hydrogen production, the conduction band (−1.4 eV) and valence band (1.3 eV) potentials of CN meet the thermodynamic conditions (3.0 > Eg > 1.23 eV) for water splitting to generate H 2 and O 2 [ 16 ].…”

Fe@g-C3N4: an effective photocatalyst for Baeyer–Villiger oxidation under visible light condition

“…It has been widely used for photocatalytic H 2 and O 2 production, selective photocatalytic organic synthesis, and degradation of organic and/or inorganic pollutants photocatalytically under visible light. [10][11][12][13][14][15] On the other hand, due to its polymeric nature, some problems still persist in using g-C 3 N 4 as a photocatalyst, such as small specific surface area, crucial photoinduced electron-hole recombination, low quantum yield, and extensive bandgap, which slow down the adequate utilization of sunlight. 16 Despite this, studies have shown that C 3 N 4 's photogenerated electrons are localized within tri-s-triazinebased building blocks, causing a high recombination rate of electron-hole pairs and preventing photocatalysis.…”