Synthesis of Ag-loaded Sb2WO6 microsphere with enhanced photocatalytic ability for organic dyes degradations under different light irradiations

Near-infrared responsive photocatalysts for environmental remediation and energy conversion: A review

Photocatalytic technology provides a vital pathway for the sustainable and efficient removal of environmental pollutants and energy conversion. However, enhancing the near-infrared (NIR) light absorption and utilization capabilities of photocatalysts has remained a significant challenge in this field. This paper presents a comprehensive review of recent developments in NIR-responsive photocatalysts. It systematically outlines strategies for improving the NIR light absorption capacity of photocatalysts, including doping engineering, upconversion, and plasmonic resonance effects. The discussion then progresses to cover advancements in NIR-responsive photocatalytic materials, highlighting the relationship between their unique physicochemical properties and corresponding modification strategies. Furthermore, the review explores the applications and mechanisms of various NIR-responsive photocatalysts in pollutant degradation, CO2 reduction, volatile organic compounds removal, and the green synthesis of H2 and H2O2. Finally, the paper addresses the challenges faced in developing NIR-responsive photocatalysts and their broader applications, proposing future research directions to mitigate these existing barriers.

Novel Z-scheme AgI/Sb2WO6 heterostructure for efficient photocatalytic degradation of organic pollutants under visible light: Interfacial electron transfer pathway, DFT calculation and mechanism unveiling

Developing highly efficient heterostructured photocatalysts with robust redox ability is of great significance to wastewater purification. Herein, a novel Z-scheme AgI/Sb2WO6 heterojunction was successfully constructed via a chemical-precipitation method. The Z-scheme system can serve as a highly efficient photocatalyst for degradation of organic pollutants in water. Under visible light illumination, the degradation efficiency of rhodamine B and tetracycline over the optimal Z-scheme heterojunction can achieve 95% in 12 min and 80% in 8 min, which is 10.8 and 11.4 times higher than that over single Sb2WO6, respectively. Interestingly, low amounts of Ag0 can be generated and attached on the surface of Sb2WO6 during the photocatalytic process, further enhancing the photocatalytic activity of the Z-scheme heterojunction. Based on theoretical calculations, the interfacial internal electric field (IEF) can facilitate the photoexcited electrons at the conduction band (CB) of AgI to consume the photoexcited holes at the valence band (VB) of Sb2WO6, which greatly promotes the Z-scheme charge transfer path. Quenching experiments and electron spin resonance analyses demonstrate superoxide radicals play a major role in the photocatalytic reactions. The concept of constructing a Z-scheme heterojunction photocatalyst with efficient interfacial charge transfer shall provide a design guide for wastewater purification.

Investigation of PEG directed Sb2WO6 for dyes removal from wastewater

Pristine and polyethylene glycol assisted antimony tungstate (Sb₂WO₆) was developed via hydrothermal route. The pristine and surfactant assisted Sb₂WO₆ were further exemplified to reveal the properties of the samples. The bandgap calculated for Sb₂WO₆, 5 ml PEG- Sb₂WO₆, 10 ml PEG- Sb₂WO₆ was 2.78 eV, 2.66 eV and 2.21 eV. The 10 ml PEG assisted sample exhibited narrow bandgap. The Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed metal vibrations and stretching of the water molecules adsorbed. The Raman spectra showed the vibrational modes present in Sb₂WO₆. The morphology was analyzed employing transmission electron microscope (TEM) for all samples. Pristine Sb₂WO₆ showed growth of nanorods with higher dimensions with high agglomeration. 5 ml PEG- Sb₂WO₆ showed the growth of nanorods with lesser agglomeration. 10 ml PEG assisted Sb₂WO₆ exhibited distinct growth of nanorods with no agglomeration on the surface. The elemental composition was examined employing X-ray Photoelectron Spectroscopy. Prepared product photocatalytic behaviour was tested employing Rhodamine B dye degrading. Different catalyst loading were investigated for degrading the toxic pollutants. 0.2 g 10 ml PEG-Sb₂WO₆ showed 81% efficiency on degrading the toxic pollutant from wastewater. The OH radicals are accountable for photocatalytic behaviour of prepared photocatalyst. The 10 ml PEG-Sb₂WO₆ has the good reusability behavior and stable properties after three cycles. The prepared 10 ml PEG- Sb₂WO₆ photocatalyst will be the potential candidate for the remediation of the water treatment.

Visible-NIR light-responsive 0D/2D CQDs/Sb2WO6 nanosheets with enhanced photocatalytic degradation performance of RhB: Unveiling the dual roles of CQDs and mechanism study

Environmental pollution caused by dye wastewater discharge has attracted much attention in the past decades. Developing photocatalysts with high solar energy utilization efficiency for the treatment of dye wastewater is one of the most promising methods to address afore-mentioned environmental problem. Herein, novel Vis-NIR (visible to near-infrared) light-responsive carbon quantum dots modified Sb₂WO₆ (CQDs/Sb₂WO₆) nanosheets with remarkably enhanced photocatalytic degradation performance of Rhodamine B (RhB) aqueous solution were successfully synthesized. Under the irradiation of Vis light, the photocatalytic degradation efficiency reaches 83% over the optimal composite, which is nearly seven times higher than that of pristine Sb₂WO₆. Meanwhile, under NIR light irradiation, the optimal composite also keeps a stable degradation performance, while pristine Sb₂WO₆ exhibits sluggish performance. Besides, a detailed photocatalytic degradation pathway was proposed via the analyses of corresponding intermediates in the photocatalytic degradation process. On the basis of electron spin resonance spectrometry, quenching experiment and density functional theory (DFT) calculation, hydroxyl radicals (•OH) play a dominating role in the photocatalytic reactions and a possible photocatalytic degradation mechanism was unearthed. This work provides new insights for constructing novel Vis-NIR responsive photocatalysts to purify dye wastewater for environmental remediation.

Highly sensitive photoelectrochemical neuron specific enolase analysis based on cerium and silver Co-Doped Sb2WO6

A signal-enhanced photoelectrochemical immunoassay technique for detecting neuron specific enolase (NSE) was proposed. As a photoactive matrix, (Ce,Ag):Sb₂WO₆ was firstly investigated via doping Ce and Ag into Sb₂WO₆. It could be found that the presence of Ce and Ag not only had enormous variation on the morphology of Sb₂WO₆, but also showed excellent PEC behavior. In order to further improve the visible light utilization rate of (Ce,Ag):Sb₂WO₆, In₂S₃ was modified onto the surface of (Ce,Ag):Sb₂WO₆ to enhance visible light absorption. In addition, the CdS/PDA was served as a secondary antibody marker to further amplify signal. Especially, PDA as an electron donor could effectively remove photogenerated holes. Meanwhile, the good matching cascade band-edge levels between CdS and Sb₂WO₆ could promote photoelectron migration, improve the PEC response, and achieve sensitive detection of NSE. Under the selected excellent conditions, the photocurrent can linearly increase with the increase of NSE concentration in the operating range from 0.1 pg/mL to 50 ng/mL, and the limit of detection is 1.57 fg/mL. The constructed immunosensor also exhibits satisfactory stability, selectivity, and reproducibility, and it creates conditions for the detection of other biomolecules.

Novel Fe2TiO5/reduced graphene oxide heterojunction photocatalyst with improved adsorption capacity and visible light photoactivity: experimental and DFT approach

The design of high-efficiency materials is a major challenge for the degradation of organic pollutants. In this work, type II p-n heterojunction photocatalyst Fe₂TiO₅/rGO, with enhanced performance, was successfully prepared through simple process. The Fe₂TiO₅/rGO composites were prepared by hosting several amounts of reduced graphene oxide (rGO) into pseudobrookite nanocrystals (Fe₂TiO₅) which were priorly synthesized by a solid-state reaction. The morphology and the properties of the as-prepared composites were characterized through different techniques. The fixation of rGO sheets on Fe₂TiO₅ was proved using the X-ray diffraction analysis (XRD). The results of the scanning electron microscope (SEM) analysis showed a good mixing of rGO with Fe₂TiO₅. The X-ray fluorescence (XRF) confirmed the purity of the pristine Fe₂TiO₅. The dynamic light scattering (DLS) illustrated a strong tendency to aggregation. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) analysis was performed to characterize the electronic aspect as the gap and the Urbach energies. Finally, computational density functional theory (DFT) calculations were carried out to confirm the experimental results. The adsorptive and photoactivity of Fe₂TiO₅/rGO heterojunction photocatalysts were evaluated by methylene blue (MB) degradation under visible light irradiation. The highest MB degradation rate was achieved for Fe₂TiO₅/rGO_10% photocatalyst with the highest value of the elimination rate.

Synthesis of CdS-loaded (CuC10H26N6)3(PW12O40)2 for enhanced photocatalytic degradation of tetracycline under simulated solar light irradiation

Largely discharged and excreted medical pollutants pose huge threats to ecosystems. However, typical photocatalysts, such as the Keggin-typed H₃PW₁₂O₄₀, can hardly degrade these hazards under visible-light due to their broad bandgap and catalytic disability. In this work, the visible light harvesting was enabled by combining macrocyclic coordination compound CuC₁₀H₂₆N₆Cl₂O₈ with H₃PW₁₂O₄₀, and the resulting CuPW was loaded with CdS to reach robust catalytic ability to totally detoxify medicines. We prepared the CuPW–CdS composites through a facile precipitation method, and it showed excellent photocatalytic degradation for degrading tetracycline under visible-light irradiation. The (CuC₁₀H₂₆N₆)₃(PW₁₂O₄₀)₂ with 10 wt% load of CdS shows the highest performance and is ∼6 times more efficient than the pure CuPW counterpart. The heterojunctional CuPW–CdS composites promote the separation of electrons and holes, and consequentially enhance photocatalytic activity. Thanks to migration of electrons from CdS to CuPW, the photocorrosion of CdS is prohibited, resulting in a high chemical stability during photocatalysis. In this work we design a new route to the multi-structural composite photocatalysts for practical applications in medical pollutant decontamination.

We demonstrated the incorporation of (CuC₁₂H₃₀N₆)²⁺ into the a Keggin type H₃PW₁₂O₄₀ by a simple one-pot self-assembly process. A heterojunction structure was constructed by introducing CdS which has high photocatalytic activities.

Facile Synthesis of Antimony Tungstate Nanosheets as Anodes for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have been widely used in the fields of smart phones, electric vehicles, and smart grids. With its opened Aurivillius structure, tungstate antimony oxide (Sb₂WO₆, SWO), constituted of {Sb₂O₂}²ⁿ⁺ and {WO₄}²ⁿ⁻, is rarely investigated as an anode for lithium-ion batteries. In this work, Sb₂WO₆ with nanosheets morphology was successfully synthesized using a simple microwave hydrothermal method and systematically studied as an anode for lithium-ion batteries. The optimal SWO (SWO-60) exhibits a high specific discharge capacity and good rate capability. The good electrochemical performance could be ascribed to mesoporous nanosheets morphology, which is favorable for the penetration of the electrolyte and charge transportation. The results show that this nanostructured SWO is a promising anode material for LIBs.