K⁺-Doped ZnO/g-C₃N₄ Heterojunction: Controllable Preparation, Efficient Charge Separation, and Excellent Photocatalytic VOC Degradation Performance

Abstract

The K+-doped ZnO/g-C3N4 heterojunction had been prepared by an electrostatic attraction self-assemble method. The charge separation efficiency of the K+-doped ZnO/g-C3N4 heterojunction was 17.6 and 2.9 times those of g-C3N4 and KZO. As expected, the K ion-doped ZnO/g-C3N4 heterojunction possessed better photocatalytic isopropanol degradation performance. The highest acetone evolution rate of K+-doped ZnO/g-C3N4 heterojunction was 28.5 ppm·min–1, which was 2.7 times better than that of g-C3N4 and 1.7 times better than that of KZO. The improvement of charge separation efficiency and photocatalytic performance of K+-doped ZnO/g-C3N4 heterojunction is mainly due to the following two points. K+-doped ZnO/g-C3N4 heterojunction with a staggered band structure could effectively improve the carrier separation. The high surface area and mesoporous structure could realize the high efficiency of mass transfer and rapid surface reaction of reactants. These K+-doped ZnO/g-C3N4 heterojunctions with high photocatalytic activities could be widely used in air purification.

2D/2D Carbon Nitride/Zn-Doped Bismuth Vanadium Oxide S-Scheme Heterojunction for Enhancing Photocatalytic CO2 Reduction into Methanol

“…For ZnBVO and CN-ZnBVO-3, the deconvoluted Bi 4f spectra (Figure d) situated at 159.0 and 164.3 eV are ascribed to Bi 4f 7/2 and Bi 4f 5/2 , and characteristic peaks centered at 517.1 and 524.3 eV belong to V 2p 3/2 and V 2p 1/2 of V 5+ (Figure e) . In addition, the Zn 2p spectra (Figure f) presents two prominent peaks positioned at 1021.1 and 1044.4 eV severally referring to Zn 2p 3/2 and Zn 2p 1/2 , in which the spin–orbit splitting of Zn 2p was 23.3 eV, manifesting that the existence of Zn 2+ in the CN-ZnBVO-3 . Notably, due to the M–O–C strong interaction in heterojunction, the V 2p and Zn 2p peaks of CN-ZnBVO-3 are slightly shifted in comparison with single ZnBVO (Figure e and f), indicating the redistribution of electrons in CN-ZnBVO-3 interface, which is beneficial to accelerating the interfacial charge separation kinetics, thus promoting photocatalytic CO 2 reduction.…”

Recent Advances on g‐C3N4 Based Photocatalysts for Typical Antibiotics Photodegradation: Preparation, Mechanism and Influencing Factors

“…[26] The K-doping resulted in a crossed energy band structure, which can make excellent the separation of carriers, and the higher specific surface area and mesoporous structure could improve the reactant mass transfer efficiency for rapid surface reactions. [57] The energy band position of noble metals is lower than the CB position of graphitic phase carbon nitride semiconductors, so that photoexcited electrons can be captured by the surface noble metal, achieving electron-hole separation and extending its light-sensitive region to the visible region. [58] The Surface Plasmon Resonance (SPR) induced by metallic nanoparticles also plays a key role in improving light absorption and carrier separation.…”

Efficient and Stable Degradation of Triazophos Pesticide by TiO2/WO3 Nanocomposites with S-Scheme Heterojunctions and Oxygen Defects

“…A growing body of research indicates that composite material photocatalysts outperform their single-component counterparts in terms of photocatalytic activity. For instance, Liu et al synthesized ZnO/g-C 3 N 4 nanocomposites that exhibited superior activity in H 2 O 2 production [31], while Wang et al TiO 2 /ZnIn 2 S 4 photocatalyst demonstrated commendable activity in CO 2 reduction [32]. Similarly, the TiO 2 /Fe 2 O 3 composite engineered by Mirmasoomi et al exhibited remarkable activity in photocatalytic pesticide degradation [33].…”