Novel P-n Li2SnO3/g-C3N4 Heterojunction With Enhanced Visible Light Photocatalytic Efficiency Toward Rhodamine B Degradation

Abstract

The design of highly efficient and stable photocatalysts to utilize solar energy is a significant challenge in photocatalysis. In this work, a series of novel p-n heterojunction photocatalysts, Li 2 SnO 3 /g-C 3 N 4 , was successfully prepared via a facile calcining method, and exhibited superior photocatalytic activity toward the photodegradation of Rhodamine B solution under visible light irradiation as compared with pure Li 2 SnO 3 and g-C 3 N 4. The maximum kinetic rate constant of photocatalytic degradation of Rhodamine B within 60 min was 0.0302 min −1 , and the composites still retained excellent performance after four successive recycles. Chemical reactive species trapping experiments and electron paramagnetic resonance demonstrated that hydroxyl radicals (•OH) and superoxide ions (•O − 2) were the dominant active species in the photocatalytic oxidation of Rhodamine B solution, while holes (h +) only played a minor role. We demonstrated that the enhancement of the photocatalytic activity could be assigned to the formation of a p-n junction photocatalytic system, which benefitted the efficient separation of photogenerated carriers. This study provides a visible light-responsive heterojunction photocatalyst with potential applications in environmental remediation.

Photocatalytic Hydrogen Generation and CO2 Conversion Using g-C3N4 Decorated Dendritic Fibrous Nanosilica: Role of Interfaces between Silica and g-C3N4

“…g-C 3 N 4 is an n-type semiconductor; hence, the flat band potential lies 0.1 eV below the conduction band minimum (CBM). 26 Therefore, the CBM of g-C 3 N 4 was −0.16 V vs RHE. From the band gap obtained from DRS spectra, the VBM was calculated to be 2.55 V vs RHE.…”

“…The flat band potential of g-C 3 N 4 was found to be −0.71 V vs SCE, i.e., −0.06 V vs RHE. g-C 3 N 4 is an n-type semiconductor; hence, the flat band potential lies 0.1 eV below the conduction band minimum (CBM) . Therefore, the CBM of g-C 3 N 4 was −0.16 V vs RHE.…”

Photocatalytic Behavior of Supported Copper Double Salt: The Role of Graphene Oxide

“…The common mechanism of heterogeneous photocatalysis with semiconductors involves the excitation of valence band electrons to the conduction band of the catalyst by irradiation with an appropriate wavelength creating thus an electron-hole pair, Figure 5. The produced electrons and holes interact with oxygen and water forming various reactive oxidative species able to oxidize RhB by a collection of specific redox reactions [32,33] which typically involve hydroxyl radicals.…”

Graphitic Carbon Nitride-Based Z-Scheme Structure for Photocatalytic CO2 Reduction

“…GCN-based heterojunction can perform charge transfer (CT) in several manners, including type I, type II, p–n junction, − and Z-scheme. ,,− Generally, type II and p-n heterojunctions are two dominant GCN-based heterostructures, but they suffer from a significant drawback of weakened CO 2 reduction capacity compared with GCN and the coupled SCs. Under irradiation, the excited electrons in GCN tend to move to the CB of the coupled SC, resulting in low reduction potential levels.…”