Plasma Ag-Modified α-Fe2O3/g-C3N4 Self-Assembled S-Scheme Heterojunctions with Enhanced Photothermal-Photocatalytic-Fenton Performances

Abstract

Low spectral utilization and charge carrier compounding limit the application of photocatalysis in energy conversion and environmental purification, and the rational construction of heterojunction is a promising strategy to break this bottleneck. Herein, we prepared surface-engineered plasma Ag-modified α-Fe2O3/g-C3N4 S-Scheme heterojunction photothermal catalysts by electrostatic self-assembly and light deposition strategy. The local surface plasmon resonance effect induced by Ag nanoparticles broadens the spectral response region and produces significant photothermal effects. The temperature of Ag/α-Fe2O3/g-C3N4 powder is increased to 173 °C with irradiation for 90 s, ~3.2 times higher than that of the original g-C3N4. The formation of 2D/2D structured S-Scheme heterojunction promotes rapid electron-hole transfer and spatial separation. Ternary heterojunction construction leads to significant enhancement of photocatalytic performance of Ag/α-Fe2O3/g-C3N4, the H2 photocatalytic generation rate up to 3125.62 µmol g−1 h−1, which is eight times higher than original g-C3N4, and the photocatalytic degradation rate of tetracycline to reach 93.6%. This thermally assisted photocatalysis strategy improves the spectral utilization of conventional photocatalytic processes and provides new ideas for the practical application of photocatalysis in energy conversion and environmental purification.

Recent Advances in Carbon Nitride-Based S-scheme Photocatalysts for Solar Energy Conversion

“…When the composite photocatalyst is excited by light, the photogenerated electrons of α-Fe 2 O 3 move to carbon nitride under the action of the interfacial electric field. At this time, g-C 3 N 4 loses electrons and α-Fe 2 O 3 gets electrons, so the binding energy of N and Fe shift positively and negatively, respectively [ 83 ]. Therefore, ISIXPS can characterize the direction of electron transfer in S-scheme heterojunctions.…”

The preserved S-scheme band structure of graphitic carbon nitride/bismuth oxobromide after the introduction of black phosphorus driven by an internal electric field: achieving significantly enhanced photocatalytic performance

“…Currently, an effective solution is to introduce a third component, which can be categorized into two main types based on the role of the third component. In the first category, the introduced third component often consists of zero-bandgap materials, such as graphene, 7 elemental metals like Ag 8,9 and Bi, 10 carbon quantum dots, 11 Ti 3 C 2 MXene, 12 etc. These materials are uniformly dispersed within the binary components and primarily serve as conductors to enhance charge carrier transport.…”

Advanced Photocatalytic Nanomaterials for Energy Conversion and Environmental Remediation

“…These eleven papers were devoted to achieving high-efficiency photocatalysts by broadening the light absorption range, inhibiting the photo-induced electrons and holes recombination, and promoting the extraction of photo-induced charges for chemical reactions. The strategies include defect engineering [1], element doping [2,3], morphology manipulation [3,4], and binary and ternary composite fabrication [5][6][7][8][9][10][11]. Herein, we will provide a brief introduction to these works.…”

“…Hence, the Cu 2 O-TiO 2 exhibits a hydrogen evolution rate tenfold higher in comparison with bare TiO 2 . Wang et al [7] reported a plasma Ag-modified α-Fe 2 O 3 /g-C 3 N 4 S-Scheme heterojunction that performed much more efficiently than the original g-C 3 N 4 in terms of photocatalytic degradation of tetracycline and hydrogen production. The introduction of Ag nanoparticles expands the light absorption and induces high-energy electrons and photothermal effects from the local surface plasmon resonance effect, which leads to improved photocatalytic activity with joint contributions from the 2D/2D S-Scheme induced electron-hole separation.…”