Sulfide-Based Photocatalysts Using Visible Light, with Special Focus on In2S3, SnS2 and ZnIn2S4

Sulfides are frequently used as photocatalysts, since they absorb visible light better than many oxides. They have the disadvantage of being more easily photocorroded. This occurs mostly in oxidizing conditions; therefore, they are commonly used instead in reduction processes, such as CO2 reduction to fuels or H2 production. Here a summary will be presented of a number of sulfides used in several photocatalytic processes; where appropriate, some recent reviews will be presented of their behaviour. Results obtained in recent years by our group using some octahedral sulfides will be shown, showing how to determine their wavelength-dependent photocatalytic activities, checking their mechanisms in some cases, and verifying how they can be modified to extend their wavelength range of activity. It will be shown here as well how using photocatalytic or photoelectrochemical setups, by combining some enzymes with these sulfides, allows achieving the photo-splitting of water into H2 and O2, thus constituting a scheme of artificial photosynthesis.

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Hierarchical assemblies of CdxZn1−xS complex architectures and their enhanced visible-light photocatalytic activities for H2-production

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2013.07.013 ◽

2013 ◽

Vol 578 ◽

pp. 571-576 ◽

Cited By ~ 11

Author(s):

Jian Wang ◽

Bo Li ◽

Jiazang Chen ◽

Li Li ◽

Jianghong Zhao ◽

...

Keyword(s):

Visible Light ◽

H2 Production ◽

Photocatalytic Activities ◽

Complex Architectures ◽

Visible Light Photocatalytic

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Charge-Transfer Regulated Visible Light Driven Photocatalytic H2 Production and CO2 Reduction in Tetrathiafulvalene Based Coordination Polymer Gel

10.21203/rs.3.rs-96702/v1 ◽

2020 ◽

Author(s):

Parul Verma ◽

Pallavi Sarkar ◽

Ashish Singh ◽

Swapan Pati ◽

Tapas Maji

Keyword(s):

Photocatalytic Activity ◽

Charge Transfer ◽

Coordination Polymer ◽

Visible Light ◽

Co2 Reduction ◽

Pt Nanoparticles ◽

H2 Production ◽

Polymer Gel ◽

H2 Evolution

Abstract The much-needed renewable alternatives to fossil fuel can be achieved efficiently and sustainably by converting solar energy to solar fuels via hydrogen generation from water or CO2 reduction. In this regard, a soft processable metal-organic hybrid semiconducting material has been developed and studied for photocatalytic activity towards H2 production and CO2 reduction to CO and CH4 under visible light and direct sunlight irradiation. A tetrapodal low molecular weight gelator is synthesized by integrating tetrathiafulvalene and terpyridine through amide linkage (TPY-TTF). The TPY-TTF acts as a linker and by self-assembly with ZnII results in a charge-transfer (CT) coordination polymer gel (CPG); Zn-TPY-TTF. The Zn-TPY-TTF shows impressive photocatalytic activity towards H2 production (rate = 530 μmol g-1h-1) and CO2 reduction to CO (rate = 438 μmol g-1h-1, selectivity >99%) regulated by charge-transfer interaction. Furthermore, in-situ stabilization of Pt nanoparticles to CPG (Pt@Zn-TPY-TTF) exhibits remarkably enhanced H2 evolution (rate =14727 μmol g-1h-1). Importantly, Pt@Zn-TPY-TTF modulate the CO2 reduction from CO to CH4 (rate = 292 μmol g-1h-1, selectivity >97%). Real-time CO2 reduction reaction is monitored by in-situ DRIFT study and subsequent plausible mechanism is derived computationally. The photocatalytic activity of Zn-TPY-TTF and Pt@Zn-TPY-TTF composite was also examined under sunlight that display excellent H2 evolution and CO2 reduction.

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Photocatalytic H2 Evolution, CO2 Reduction, and NOx Oxidation by Highly Exfoliated g-C3N4

Catalysts ◽

10.3390/catal10101147 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1147

Author(s):

Nadia Todorova ◽

Ilias Papailias ◽

Tatiana Giannakopoulou ◽

Nikolaos Ioannidis ◽

Nikos Boukos ◽

...

Keyword(s):

Visible Light ◽

Specific Surface ◽

Surface Area ◽

Photocatalytic Performance ◽

Uv Light ◽

Co2 Reduction ◽

H2 Production ◽

Thermal Treatments ◽

H2 Evolution ◽

Photocatalytic H2 Evolution

g-C3N4, with specific surface area up to 513 m2/g, was prepared via three successive thermal treatments at 550 °C in air with gradual precursor mass decrease. The obtained bulk and exfoliated (1ex, 2ex and 3ex) g-C3N4 were characterized and tested as photocatalysts for H2 production, CO2 reduction and NOx oxidation. The exfoliated samples demonstrated graphene-like morphology with detached (2ex) and sponge-like framework (3ex) of layers. The surface area increased drastically from 20 m2/g (bulk) to 513 m2/g (3ex). The band gap (Eg) increased gradually from 2.70 to 3.04 eV. Superoxide radicals (·O2−) were mainly formed under UV and visible light. In comparison to the bulk, the exfoliated g-C3N4 demonstrated significant increase in H2 evolution (~6 times), CO2 reduction (~3 times) and NOx oxidation (~4 times) under UV light. Despite the Eg widening, the photocatalytic performance of the exfoliated g-C3N4 under visible light was improved too. The results were related to the large surface area and low e−-h+ recombination. The highly exfoliated g-C3N4 demonstrated selectivity towards H2 evolution reactions.

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