A General Strategy toward Carbon Cloth-Based Hierarchical Films Constructed by Porous Nanosheets for Superior Photocatalytic Activity

Roles of CeO2 in preparing Ce-doped CdIn2S4 with boosted photocatalytic degradation performance for methyl orange and tetracycline hydrochloride

Element doping is considered as a feasible strategy to develop efficient photocatalysts. In this study, a Ce-doped CdIn2S4 photocatalyst was prepared through a modified coprecipitation method. During the synthesis of Ce-doped CdIn2S4, the CeO2 nanorods were gradually reduced by the decomposition products of thioacetamide (TAA), and mainly existed as Ce(III) in the supernatant. This resulted in a large increase in the specific surface area of the as-obtained products, providing more exposed active sites for the reactant. Additionally, a trace amount of Ce was doped into the lattice of the CdIn2S4, resulting in a significant effect on the band structure. By tracing the roles of CeO2 during the synthesis process, a possible reaction mechanism was proposed. Benefiting from the synergistic advantages of the structural and compositional features, the optimal sample showed enhanced photocatalytic activities for the degradation of methyl orange (94.6% within 25 min) and tetracycline hydrochloride (85.6% within 120 min). The degradation rates were 13.3 times and 2.7 times higher than that of pristine CdIn2S4. This work may provide a strategy for designing metal element doped photocatalysts with good activity for pollutant removal.

Visible light driven antibiotics degradation using S-scheme Bi2WO6/CoIn2S4 heterojunction: Mechanism, degradation pathways and toxicity assessment

S-scheme heterojunction photocatalysts with strong redox ability and excellent photocatalytic activity are highly desired for photocatalytic degradation of pollutants. Herein, S-scheme Bi₂WO₆/CoIn₂S₄ heterojunctions were synthesized using hydrothermal method. The photo-induced carriers transfer mechanism of the S-scheme Bi₂WO₆/CoIn₂S₄ heterojunction was clarified by band structure analysis, ultraviolet photoelectron spectrometer (UPS), electron spin resonance (ESR) and radical trapping experiments. Significant enhance of light absortion, and more efficient carriers separation were observed from the Bi₂WO₆/CoIn₂S₄ with CoIn₂S₄ nanoclusters growing on the surface of petal-like Bi₂WO₆ nanosheets. TC degradation efficiency of 90% was achieved by Bi₂WO₆/CoIn₂S₄ (15:1) within 3 h of irradiation, and ·O₂^-and ·OH radicals were dominated contributors. Possible decomposition pathways of TC were proposed, and ECOSAR analysis showed that most of the intermediates exhibited lower ecotoxicity than TC. This work provides reference on the constructing ternary-metal-sulfides-based S-scheme heterojunctions for improving photocatalytic performance.

Photocatalyst prepared by NiCo2O4/CNQDs modified carbon fabric heterojunctions enhanced visible-light-driven photocatalytic degradation of Methyl Orange

As this point, A novel photocatalyst was reported by us, cobalt nickel tetroxide (NiCo2O4)/g-C3N4 quantum dots (CNQDs) heterojunctions on carbon cloth (CC). NiCo2O4 nanosheets and NiCo2O4/CNQDs were grown on carbon...

Construction of Electrostatic Self-Assembled 2D/2D CdIn2S4/g-C3N4 Heterojunctions for Efficient Visible-Light-Responsive Molecular Oxygen Activation

Molecular oxygen activated by visible light to generate radicals with high oxidation ability exhibits great potential in environmental remediation The efficacy of molecular oxygen activation mainly depends on the separation and migration efficiency of the photoinduced charge carriers. In this work, 2D/2D CdIn₂S₄/g-C₃N₄ heterojunctions with different weight ratios were successfully fabricated by a simple electrostatic self-assembled route. The optimized sample with a weight ratio of 5:2 between CdIn₂S₄ and g-C₃N₄ showed the highest photocatalytic activity for tetracycline hydrochloride (TCH) degradation, which also displayed good photostability. The enhancement of the photocatalytic performance could be ascribed to the 2D/2D heterostructure; this unique 2D/2D structure could promote the separation and migration of the photoinduced charge carriers, which was beneficial for molecular oxygen activation, leading to an enhancement in photocatalytic activity. This work may possibly provide a scalable way for molecular oxygen activation in photocatalysis.

Flexible 3D carbon cloth as a high-performing electrode for energy storage and conversion

High-performance energy storage and conversion devices with high energy density, power density and long-term cycling life are of great importance in current consumer electronics, portable electronics and electric vehicles. Carbon materials have been widely investigated and utilized in various energy storage and conversion devices due to their excellent conductivity, mechanical and chemical stability, and low cost. Abundant excellent reviews have summarized the most recent progress and future outlooks for most of the current prime carbon materials used in energy storage and conversion devices, such as carbon nanotubes, fullerene, graphene, porous carbon and carbon fibers. However, the significance of three-dimensional (3D) commercial carbon cloth (CC), one of the key carbon materials with outstanding mechanical stability, high conductivity and flexibility, in the energy storage and conversion field, especially in wearable electronics and flexible devices, has not been systematically summarized yet. In this review article, we present a careful investigation of flexible CC in the energy storage and conversion field. We first give a general introduction to the common properties of CC and the roles it has played in energy storage and conversion systems. Then, we meticulously investigate the crucial role of CC in typical electrochemical energy storage systems, including lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries and supercapacitors. Following a description of the wide application potential of CC in electrocatalytic hydrogen evolution, oxygen evolution/reduction, full-water splitting, etc., we will give a brief introduction to the application of CC in the areas of photocatalytically and photoelectrochemically induced solar energy conversion and storage. The review will end with a brief summary of the typical superiorities that CC has in current energy conversion and storage systems, as well as providing some perspectives and outlooks on its future applications in the field. Our main interest will be focused on CC-based flexible devices due to the inherent superiority of CC and the increasing demand for flexible and wearable electronics.

Facile Synthesis of Novel CaIn₂S₄/ZnIn₂S₄ Composites with Efficient Performance for Photocatalytic Reduction of Cr(VI) under Simulated Sunlight Irradiation

A series of novel and efficient heterostructured composites CaIn₂S₄/ZnIn₂S₄ have been synthesized using a facile hydrothermal method. XRD patterns indicate the as-prepared catalysts are two-phase composites of cubic phase CaIn₂S₄ and hexagonal phase ZnIn₂S₄. FESEM (field emission scanning electron microscope) images display that the synthesized composites are composed of flower-like microspheres with wide diameter distribution. UV–Vis diffuse reflectance spectra (DRS) show that the optical absorption edges of the CaIn₂S₄/ZnIn₂S₄ composites shift toward longer wavelengths with the increase of the CaIn₂S₄ component. The photocatalytic activities of the as-synthesized composites are investigated by using the aqueous-phase Cr(VI) reduction under simulated sunlight irradiation. This is the first report on the application of the CaIn₂S₄/ZnIn₂S₄ composites as stable and efficient photocatalysts for the Cr(VI) reduction. The fabricated CaIn₂S₄/ZnIn₂S₄ composites possess higher photocatalytic performance in comparison with pristine CaIn₂S₄ or ZnIn₂S₄. The CaIn₂S₄/ZnIn₂S₄ composite with a CaIn₂S₄ molar content of 30% exhibits the optimum photocatalytic activity. The primary reason for the significantly enhanced photoreduction activity is proved to be the substantially improved separation efficiency of photogenerated electrons/holes caused by forming the CaIn₂S₄/ZnIn₂S₄ heterostructured composites. The efficient charge separation can be evidenced by steady-state photoluminescence spectra (PLs) and transient photocurrent response. Based on the charge transfer between CaIn₂S₄ and ZnIn₂S₄, an enhancement mechanism of photocatalytic activity and stability for the Cr(VI) reduction is proposed.

Enhanced visible-light photocatalytic H2-generation activity of carbon/g-C3N4 nanocomposites prepared by two-step thermal treatment

Brown carbon/g-C₃N₄ nanocomposites synthesized by two-step calcination exhibited a wide visible light response range and improved photocatalytic H₂-generation performance.

Hierarchical CdIn2S4 microspheres wrapped by mesoporous g-C3N4 ultrathin nanosheets with enhanced visible light driven photocatalytic reduction activity

In this investigation, a series of hierarchical CdIn₂S₄/g-C₃N₄ nanocomposites were firstly synthesized by a facile one-pot hydrothermal strategy, wherein the mesoporous g-C₃N₄ nanosheets were in-situ self-wrapped onto CdIn₂S₄ nanosheets. Systematic characterization by XRD, FT-IR, UV-vis DRS, SEM, TEM, HAAF-STEM, XPS, photoelectrochemical tests were employed to analyze the phase structure, chemical composition, morphology and photocatalytic mechanism. The application, including photo-redox reaction and photocatalytic water splitting, were used to estimate the photocatalytic activity of as-obtained CdIn₂S₄/g-C₃N₄ nanocomposites. The results indicate that CdIn₂S₄/g-C₃N₄ heterostructures exhibit more efficient improvement of the photocatalytic performances towards photo-reduction of 4-NA to corresponding 4-PDA and photocatalytic H₂ generation from water splitting than these counterparts as results of construction of intimate interfacial contact, which would promote the separation of photo-generated holes and electrons. Meanwhile, benefitting from the excellent surface wrap, the CdIn₂S₄/g-C₃N₄ nanocomposites possess notable enhanced photocatalytic stability. This research may provide a promising way to fabricate highly efficient photocatalysts with excellent stability and expand the application of CdIn₂S₄ in fine chemical engineering.

Graphene in Photocatalysis: A Review

In recent years, heterogeneous photocatalysis has received much research interest because of its powerful potential applications in tackling many important energy and environmental challenges at a global level in an economically sustainable manner. Due to their unique optical, electrical, and physicochemical properties, various 2D graphene nanosheets-supported semiconductor composite photocatalysts have been widely constructed and applied in different photocatalytic fields. In this review, fundamental mechanisms of heterogeneous photocatalysis, including thermodynamic and kinetics requirements, are first systematically summarized. Then, the photocatalysis-related properties of graphene and its derivatives, and design rules and synthesis methods of graphene-based composites are highlighted. Importantly, different design strategies, including doping and sensitization of semiconductors by graphene, improving electrical conductivity of graphene, increasing eloectrocatalytic active sites on graphene, strengthening interface coupling between semiconductors and graphene, fabricating micro/nano architectures, constructing multi-junction nanocomposites, enhancing photostability of semiconductors, and utilizing the synergistic effect of various modification strategies, are thoroughly summarized. The important applications including photocatalytic pollutant degradation, H₂ production, and CO₂ reduction are also addressed. Through reviewing the significant advances on this topic, it may provide new opportunities for designing highly efficient 2D graphene-based photocatalysts for various applications in photocatalysis and other fields, such as solar cells, thermal catalysis, separation, and purification.

High Efficient Photo-Fenton Catalyst of α-Fe2O3/MoS2 Hierarchical Nanoheterostructures: Reutilization for Supercapacitors

A novel three-dimensional (3D) α-Fe₂O₃/MoS₂ hierarchical nanoheterostructure is effectively synthesized via a facile hydrothermal method. The zero-dimensional (0D) Fe₂O₃ nanoparticles guide the growth of two-dimensional (2D) MoS₂ nanosheets and formed 3D flower-like structures, while MoS₂ facilitates the good dispersion of porous Fe₂O₃ with abundant oxygen vacancies. This charming 3D-structure with perfect match of non-equal dimension exhibits high recyclable photo-Fenton catalytic activity for Methyl orange pollutant and nice specific capacity in reusing as supercapacitor after catalysis. The synergistic effect between Fe₂O₃ and MoS₂, the intermediate nanointerfaces, the 3D porous structures, and the abundant oxygen vacancies both contribute to highly active catalysis, nice electrochemical performance and stable cycling. This strategy is simple, cheap, and feasible for maximizing the value of the materials, as well as eliminating the secondary pollution.