A novel hollow-hierarchical structured Bi2WO6 with enhanced photocatalytic activity for CO2 photoreduction

Facile synthesis of Bi3O(OH)(AsO4)2 and simultaneous photocatalytic oxidation and adsorption of Sb(III) from wastewater

Antimony (Sb) decontamination in water is necessary owing to the worsening pollution which seriously threatens human life safety. Designing bismuth-based photocatalysts with hydroxyls have attracted growing interest because of the broad bandgap and enhanced separation efficiency of photogenerated electron/hole pairs. Until now, the available photocatalysis information regarding bismuth-based photocatalysts with hydroxyls has remained scarce and the contemporary report has been largely limited to Bi3O(OH)(PO4)2 (BOHP). Herein, Bi3O(OH)(AsO4)2 (BOHAs), a novel ultraviolet photocatalyst, was fabricated via the co-precipitation method for the first time, and developed to simultaneous photocatalytic oxidation and adsorption of Sb(III). The rate constant of Sb(III) removal by the BOHAs was 32.4, 3.0, and 4.3 times higher than those of BiAsO4, BOHP, and TiO2, respectively, indicating that the introduction of hydroxyls could increase the removal of Sb(III). Additionally, the crucial operational parameters affecting the adsorption performance (catalyst dosage, concentration, pH, and common anions) were investigated. The BOHAs maintained 85% antimony decontamination of the initial yield after five successive cycles of photocatalysis. The Sb(III) removal involved photocatalytic oxidation of adsorbed Sb(III) and subsequent adsorption of the yielded Sb(V). With the acquired knowledge, we successfully applied the photocatalyst for antimony removal from industrial wastewater. In addition, BOHAs could also be powerful photocatalysts in the photodegradation of organic pollutants studies of which are ongoing. It reveals an effective strategy for synthesizing bismuth-based photocatalysts with hydroxyls and enhancing pollutants' decontamination.

Constructing a 3D Bi2WO6/ZnIn2S4 direct Z-scheme heterostructure for improved photocatalytic CO2 reduction performance

Developing efficient heterojunction photocatalysts with enhanced charge transfer and reduced recombination rates of photogenerated carriers is crucial for harnessing solar energy in the photocatalytic CO2 reduction into renewable fuels. This study employed electrostatic self-assembly techniques to construct a 3D Bi2WO6/ZnIn2S4 direct Z-scheme heterojunctions. The unique 3D structure provided abundant active sites and facilitated CO2 adsorption. Moreover, the optimized Bi2WO6/ZnIn2S4 composite demonstrated an impressive CH4 yield of 19.54 μmol g-1 under 4 h of simulated sunlight irradiation, which was about 8.73 and 16.30-fold higher than pure ZnIn2S4 and Bi2WO6. The observed enhancements in photocatalytic performance are attributed to forming a direct Z-scheme heterojunction, which effectively promotes charge transport and migration. This research introduces a novel strategy for constructing photocatalysts through the synergistic effect of morphological interface modifications.

Fabrication of pure Bi2WO6 and Bi2WO6/MWCNTs nanocomposite as potential antibacterial and anticancer agents

An essential research area for scientists is the development of high-performing, inexpensive, non-toxic antibacterial materials that prevent the transfer of bacteria. In this study, pure Bi2WO6 and Bi2WO6/MWCNTs nanocomposite were prepared by hydrothermal method. A series of characterization results by using XRD FTIR, Raman, FESEM, TEM, and EDS analyses, reveal the formation of orthorhombic nanoflakes Bi2WO6 by the addition of NaOH and pH adjustment to 7. Compared to pure Bi2WO6, the Bi2WO6/MWCNTs nanocomposite exhibited that CNTs are efficiently embedded into the structure of Bi2WO6 which results in charge transfer between metal ion electrons and the conduction or valence band of Bi2WO6 and MWCNTs and result in shifting to longer wavelength as shown in UV-visible and PL. The results confirmed that MWCNTs are stuck to the surface of the microflowers, and some of them embedded inside the Bi2WO6 nanoflakes without affecting the structure of Bi2WO6 nanoflakes as demonstrated by TEM. In addition, Pure Bi2WO6 and the Bi2WO6/MWCNTs nanocomposite were tested against P. mirabilis and S. mutans., confirming the effect of addition MWCNTs materials had better antibacterial activity in opposition to both bacterial strains than pure Bi2WO6. Besides, pure Bi2WO6 and the Bi2WO6/MWCNTs nanocomposite tested for cytotoxicity against lung MTT test on Hep-G2 liver cancer cells, and flow-cytometry. Results indicated that pure Bi2WO6 and the Bi2WO6/MWCNTs nanocomposite have significant anti-cancer efficacy against Hep-G2 cells in vitro. In addition, the findings demonstrated that Bi2WO6 and Bi2WO6/MWCNTs triggered cell death via increasing ROS. Based on these findings, it appears that pure Bi2WO6 and the Bi2WO6/MWCNTs nanocomposite have the potential to be developed as nanotherapeutics for the treatment of bacterial infections, and liver cancer.

Construction of graphene oxide-coated zinc tetraphenyporphyrin nanostructures for photocatalytic CO2 reduction to highly selective CH4 product

The zinc-based photocatalysts for CO₂ reduction have attracted increasing attention, however, usually exhibit low CO₂-to-CH₄ selectivity. Here, the graphene oxide (GO)-coated zinc tetraphenylporphyrin (ZnTPP/GO) nanocomposites are successfully synthesized through a simple method. It is found that with the increase of GO content, the crystallinity of ZnTPP nanocrystals enhances with the size decrease, and then the light absorption can easily match with the solar spectrum. The optimal ZnTPP/GO sample exhibits the CH₄ evolution rate of 41.6 μmol g^-1 h^-1 and CH₄ selectivity of >95%, which are higher than those of ZnTPP nanocrystals (7.8 μmol g^-1 h^-1 and 50.3%). The systematic characterizations confirm that the generation of axial coordinated ZnOC bonds between ZnTPP and GO plays a key role in the formation of ZnTPP/GO nanostructure and their synergic effect on photocatalytic CO₂ reduction. The encapsulation of GO on ZnTPP nanocrystals not only promotes the CO₂ adsorption, interfacial reaction, and stability, but also accelerates the separation of photoinduced carriers on ZnTPP (0.1 ps vs. 425.9 ps), the transportation from ZnTPP to GO (2.3 ps vs. 83.6 ps), and their final enrichment on GO. This work provides a new strategy to apply graphene and organic nanomaterials in artificial photosynthesis.

Interfacial construction of P25/Bi2WO6 composites for selective CO2 photoreduction to CO in gas-solid reactions

Photocatalysis provides an attractive approach to convert CO₂ into valuable fuels, which relies on a well-designed photocatalyst with good selectivity and high CO₂ reduction ability. Herein, a series of P25/Bi₂WO₆ nanocomposites were synthesized by a simple one-step in situ hydrothermal method. The formation of a heterojunction between Bi₂WO₆, which absorbs visible light, and P25, which absorbs ultraviolet light, expands the utilization of sunlight by the catalysts, and consequently, leads to a remarkably enhanced CO₂ selective photoreduction to CO. The maximum CO yield of the P25/Bi₂WO₆ heterojunction under simulated solar irradiation was 15.815 μmol g^-1 h^-1, which was 4.04 and 2.80 times higher than that of pure P25 and Bi₂WO₆, respectively. Our investigations verified a Z-scheme charge migration mechanism based on various characterization techniques between P25 and Bi₂WO₆. Furthermore, in situ DRIFTS uncovered the related reaction intermediates and CO₂ photoreduction mechanism. Our work sheds light on investigating the efficacious construction of Bi₂WO₆-based hybrids for light-driven photocatalysis.

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

One of the most enticing approaches to environmental restoration and energy conversion is photocatalysis powered by solar light. Traditional photocatalysts have limited practical uses due to inadequate light absorption, charge separation, and unknown reaction mechanisms. Discovering new visible-light photocatalysts and investigating their modification is crucial in photocatalysis. Bi-based photocatalytic nanomaterials have gotten much interest as they exhibit distinctive geometric shapes, flexible electronic structures, and good photocatalytic performance under visible light. They can be employed as stand-alone photocatalysts for pollution control and energy production, but they do not have optimum efficacy. As a result, their photocatalytic effectiveness has been significantly improved in the recent decades. Numerous newly created concepts and methodologies have brought significant progress in defining the fundamental features of photocatalysts, upgrading the photocatalytic ability, and understanding essential reactions of the photocatalytic process. This paper provides insights into the characteristics of Bi-based photocatalysts, making them a promising future nanomaterial for environmental remediation. The current review discusses the fabrication techniques and enhancement in Bi-based semiconductor photocatalysts. Various environmental applications, such as H2 generation and elimination of water pollutants, are also discussed in terms of semiconductor photocatalysis. Future developments will be guided by the uses, issues, and possibilities of Bi-based photocatalysts.

Recent review of BixMOy (M=V, Mo, W) for photocatalytic CO2 reduction into solar fuels

The utilization of solar energy for CO₂ conversion not only enables a green and low-carbon recycling of CO₂ with renewable energy, but also solves ecological problems. Bi_xMO_y (M = V, Mo, W) materials have typical layered structures and unique electronic properties that provide suitable band gaps and potential to meet the basic conditions for CO₂ reduction. However, pristine Bi_xMO_y faces with problems such as small specific surface area, insufficient active sites, low charge carriers' separation and utilization efficiency. This review comprehensively described the basic principles and reaction pathways of photocatalytic CO₂ reduction, and further presented the research progress of Bi_xMO_y catalysts in CO₂ conversion reactions. In this perspective, we further focus on the design concepts and modification strategies to improve the photocatalytic CO₂ reduction activity of Bi_xMO_y, such as morphology control, constructing surface vacancies and heterojunction fabrication. Finally, based on representative researches, the present review will be expected to provide updated information and insights for developing advanced Bi_xMO_y materials to further improve CO₂ reduction activity and selectivity.

Rational Regulation of Electronic Structure in Layered Double Hydroxide Via Vanadium Incorporation to Trigger Highly Selective CO2 Photoreduction to CH4

To realize excellent selectivity of CH₄ in CO₂ photoreduction (CO₂ PR) is highly desirable, yet which is challenging due to the limited active sites for CH₄ generation and severe electron-hole recombination on photocatalysts. Herein, based on the theoretically calculated effects of vanadium incorporation into the laminate of layered double hydroxides (LDHs), V into NiAl-LDH to synthesize a series of LDHs with various V contents is introduced. NiV-LDH is revealed to afford a high CH₄ selectivity (78.9%), and extremely low H₂ selectivity (only 0.4%) under λ > 400 nm irradiation. By further tuning the molar ratio of Ni to V, a CH₄ selectivity of as high as 90.1% is achieved on Ni₄ V-LDH, and H₂ is completely prohibited on Ni₂ V-LDH. Fine structural characterizations and comprehensive optical and electrochemical studies uncover V incorporation creates the lower-valence Ni species as active sites for generating CH₄ , and enhances the generation, separation, and transfer of photogenerated carriers.

Photoreduction of CO2 into CH4 Using Novel Composite of Triangular Silver Nanoplates on Graphene-BiVO4

Plasmonic photocatalysis, combing noble metal nanoparticles (NMNPs) with semiconductors, has been widely studied and proven to perform better than pure semiconductors. The plasmonic effects are mainly based on the localized surface plasmon resonance (LSPR) of NMNPs. The LSPR wavelength depends on several parameters, such as size, shape, the surrounding media, and the interdistance of the NMNPs. In this study, graphene-modified plate-like BiVO4 composites, combined with silver nanoplates (AgNPts), were successfully prepared and used as a photocatalyst for CO2 photoconversion. Triangular silver nanoplates (TAgNPts), icosahedral silver nanoparticles (I-AgNPs), and decahedra silver nanoparticles (D-AgNPs) were synthesized using photochemical methods and introduced to the nanocomposites to compare the shape-dependent plasmonic effect. Among them, T-AgNPts/graphene/BiVO4 exhibited the highest photoreduction efficiency of CO2 to CH4, at 18.1 μmolg−1h−1, which is 5.03 times higher than that of pure BiVO4 under the irradiation of a Hg lamp. A possible CO2 photoreduction mechanism was proposed to explain the synergetic effect of each component in TAgNPts/graphene/BiVO4. This high efficiency reveals the importance of considering the compositions of photocatalysts for converting CO2 to solar fuels.

Insight into the Roles of Metal Loading on CO2 Photocatalytic Reduction Behaviors of TiO2

The photocatalytic reduction of carbon dioxide (CO₂) into value-added chemicals is considered to be a green and sustainable technology, and has recently gained considerable research interest. In this work, titanium dioxide (TiO₂) supported Pt, Pd, Ni, and Cu catalysts were synthesized by photodeposition. The formation of various metal species on an anatase TiO₂ surface, after ultraviolet (UV) light irradiation, was investigated insightfully by the X-ray absorption near edge structure (XANES) technique. CO₂ reduction under UV-light irradiation at an ambient pressure was demonstrated. To gain an insight into the charge recombination rate during reduction, the catalysts were carefully investigated by the intensity modulated photocurrent spectroscopy (IMPS) and photoluminescence spectroscopy (PL). The catalytic behaviors of the catalysts were investigated by density functional theory using the self-consistent Hubbard U-correction (DFT+U) approach. In addition, Mott–Schottky measurement was employed to study the effect of energy band alignment of metal-semiconductor on CO₂ photoreduction. Heterojunction formed at Pt-, Pd-, Ni-, and Cu-TiO₂ interface has crucial roles on the charge recombination and the catalytic behaviors. Furthermore, it was found that Pt-TiO₂ provides the highest methanol yield of 17.85 µmol/g_cat/h, and CO as a minor product. According to the IMPS data, Pt-TiO₂ has the best charge transfer ability, with the mean electron transit time of 4.513 µs. We believe that this extensive study on the junction between TiO₂ could provide a profound understanding of catalytic behaviors, which will pave the way for rational designs of novel catalysts with improved photocatalytic performance for CO₂ reduction.

Facile solvothermal assisted g-C3N4 post-grafting with aromatic amine dyes for effective photocatalytic hydrogen evolution

Dye grafted g-C3N4 using covalent bonds via a Schiff base chemical reaction exhibit much higher photocatalytic activity for H2 evolution.

A Critical Review on Black Phosphorus-Based Photocatalytic CO2 Reduction Application

Energy shortages and greenhouse effects are two unavoidable problems that need to be solved. Photocatalytically converting CO₂ into a series of valuable chemicals is considered to be an effective means of solving the above dilemmas. Among these photocatalysts, the utilization of black phosphorus for CO₂ photocatalytic reduction deserves a lightspot not only for its excellent catalytic activity through different reaction routes, but also on account of the great preponderance of this relatively cheap catalyst. Herein, this review offers a summary of the recent advances in synthesis, structure, properties, and application for CO₂ photocatalytic reduction. In detail, the review starts from the basic principle of CO₂ photocatalytic reduction. In the following section, the synthesis, structure, and properties, as well as CO₂ photocatalytic reduction process of black phosphorus-based photocatalyst are discussed. In addition, some possible influencing factors and reaction mechanism are also summarized. Finally, a summary and the possible future perspectives of black phosphorus-based photocatalyst for CO₂ reduction are established.

Interfacial charge dynamics in type-II heterostructured sulfur doped-graphitic carbon nitride/bismuth tungstate as competent photoelectrocatalytic water splitting photoanode

Sluggish charge transfers at the electrode/electrolyte interface and fast recombination of electron-hole pairs limit the photoelectrocatalytic water-splitting ability of the bismuth tungstate (Bi₂WO₆). To address these issues, sulfur doped-graphitic carbon nitride/bismuth tungstate (S-g-C₃N₄/Bi₂WO₆) heterostructured hybrid material with different wt% of S-g-C₃N₄ were constructed via an ultrasonic approach. The formation of heterostructure offers well-separated electron-hole pairs, thereby improving the charge transfer process, and boosting water oxidation kinetics on the surface of modified electrodes. Electrochemical impedance analysis confirms the rapid charge transfer process and quick electrochemical reaction at the electrode/electrolyte interface, which quenches the charge recombination process. The S-g-C₃N₄/Bi₂WO₆ with 3 wt% of S-g-C₃N₄ photoanode delivers ~43, ~18 and ~2-folds higher applied bias photon-to-current efficiency than S-g-C₃N₄, Bi₂WO₆, and g-C₃N₄/Bi₂WO₆ (3 wt% of g-C₃N₄) photoanodes, respectively. From the combination of UV-Vis, XPS valance band, and Mott-Schottky analysis the plausible band edge positions of the Bi₂WO₆ and S-g-C₃N₄ were calculated. Based on the band structure, we have concluded that the S-g-C₃N₄/Bi₂WO₆ hybrid photoanode follows a type-II charge transfer mechanism to promote the photoelectrocatalytic water splitting ability.

Synergistic catalysis of BiOIO3 catalyst for elimination of organic pollutants under simultaneous photo-irradiation and ultrasound-vibration treatment

Development of efficiently catalytic strategy for oxidative purification of organic pollutants is of great significance. Photocatalysis has become one of the most important technologies in the past half a century, but the inefficiency of photocatalysts drastically suppresses its practical application. This work proposes a synergistic photopiezocatalysis of BiOIO₃ under simultaneous photo-irradiation and ultrasound-vibration treatment to degrade various organic pollutants. Different from the high recombination of photo-excited charges in photocatalysis, the ultrasound-induced stress deforms the pyroelectric BiOIO₃ to form a piezoelectric potential that drives photo-/thermo-generated free electrons and holes in catalyst to diffuse along opposite directions. In comparison with the single photocatalysis and piezocatalysis, the photopiezocatalysis possesses a synergistic effect, presenting evidently enhanced catalytic performance for decomposing a variety of organic dyes and a persistent organic pollutant 2,4-DCP. No apparent decrease in activity during successive five runs demonstrates that the photopiezocatalysis of BiOIO₃ has a high stability and reusability. Finally, a plausible photopiezocatalysis mechanism is proposed based on the determination of active species produced on catalyst and intermediates during pollutant degradation. Our findings provide a new insight to promote charge separation and meanwhile develop an efficient synergistic photopiezocatalysis for environment remediation.

Direct Z-Scheme 0D/2D Heterojunction of CsPbBr3 Quantum Dots/Bi2WO6 Nanosheets for Efficient Photocatalytic CO2 Reduction

Photocatalytic CO₂ reduction is an appealing approach to convert solar energy into high value-added chemicals. All-inorganic CsPbBr₃ quantum dots (QDs) have emerged as a promising photocatalyst for reducing CO₂. However, pristine CsPbBr₃ has a low catalytic performance, mainly due to severe charge recombination. Herein, a 0D/2D heterojunction of CsPbBr₃ QDs/Bi₂WO₆ nanosheet (CPB/BWO) photocatalysts is fabricated for photocatalytic CO₂ reduction. The CPB/BWO photocatalyst achieves excellent photocatalytic performance: the total yield of CH₄/CO is 503 μmol g^-1, nearly 9.5 times higher than the pristine CsPbBr₃. The CPB/BWO heterojunction also exhibits much-improved stability during photocatalytic reactions. On the basis of various characterization techniques, our investigations verified a direct Z-scheme charge migration mechanism between CsPbBr₃ QDs and Bi₂WO₆ nanosheets. The improved photocatalytic performance is originated from the high spatial separation of photoexcited charge carriers in CPB/BWO, which can also preserve strong individual redox abilities of two components. This work reports an efficient direct Z-scheme heterojunction photocatalytic system based on metal halide perovskites. The novel strategy we proposed may bring up new opportunities for the development of metal halide perovskite photocatalysts with greatly enhanced activities.

CuMoxW(1-x)O4 Solid Solution Display Visible Light Photoreduction of CO2 to CH3OH Coupling with Oxidation of Amine to Imine

The photoreduction of carbon dioxide (CO₂) to valuable fuels is a promising strategy for the prevention of rising atmospheric levels of CO₂ and the depletion of fossil fuel reserves. However, most reported photocatalysts are only active in the ultraviolet region, which necessitates co-catalysts and sacrificial agents in the reaction systems, leading to an unsatisfied economy of the process in energy and atoms. In this research, a CuMo_xW_(1-x)O₄ solid solution was synthesized, characterized, and tested for the photocatalytic reduction of CO₂ in the presence of amines. The results revealed that the yield of CH₃OH from CO₂ was 1017.7 μmol/g under 24 h visible light irradiation using CuW_0.7Mo_0.3O₄ (x = 0.7) as the catalyst. This was associated with the maximum conversion (82.1%) of benzylamine to N-benzylidene benzylamine with high selectivity (>99%). These results give new insight into the photocatalytic reduction of CO₂ for valuable chemical products in an economic way.

Enhanced photocatalytic degradation of organic pollutants using carbon nanotube mediated CuO and Bi2WO6 sandwich flaky structures

CuO/CNT/Bi2WO6 composites were synthesized with a solvothermal and impregnation-calcination method. This material combines the advantages of CuO, carbon nanotubes (CNTs) and Bi2WO6. The photocatalytic activity of the catalyst was evaluated by degrading phenolic organic pollutants such as p-nitrophenol and phenol under visible light. Compared with pure Bi2WO6, the photocatalytic activity of CuO/CNT/Bi2WO6 composites is significantly increased by a factor of 3.52. The main reason for the increased activity is that the doped CNTs and CuO promote the separation of photogenerated hole and electron pairs. In addition, the coupling of π-π electrons on the CNT surface with the pollutants promotes the adsorption of the pollutants on the photocatalyst surface. The degradation rate of pure photocatalytic degradation of phenol can reach 60%. Under the synergistic effect of H2O2, the degradation rate of phenol can reach 94%, which is 1.56 times higher than that of pure photocatalysis. The UV-vis absorption spectrum shows that CuO/CNT/Bi2WO6 has stronger light absorption ability in both visible and ultraviolet light regions. The trapping experiments of active species show that h + and • OH are the main active substances for photocatalytic degradation of phenol. This paper proposes a Z scheme mechanism to improve the photocatalytic performance.

Highly Luminescent and Water-Resistant CsPbBr3-CsPb2Br5 Perovskite Nanocrystals Coordinated with Partially Hydrolyzed Poly(methyl methacrylate) and Polyethylenimine

All inorganic lead halide perovskite nanocrystals (PNCs) typically suffer from poor stability against moisture and UV radiation as well as degradation during thermal treatment. The stability of PNCs can be significantly enhanced through polymer encapsulation, often accompanied by a decrease of photoluminescence quantum yield (PLQY) due to the loss of highly dynamic oleylamine/oleic acid (OLA/OA) ligands. Herein, we propose a solution for this problem by utilizing partially hydrolyzed poly(methyl methacrylate) (h-PMMA) and highly branched poly(ethylenimine) (b-PEI) as double ligands stabilizing the PNCs already during the mechanochemical synthesis (grinding). The hydrophobic polymer of h-PMMA imparts excellent film-forming properties and water stability to the resulting NC-polymer composite. In its own turn, the b-PEI forms an amino-rich, strongly binding ligand layer on the surface of the PNCs being responsible for the significant improvement of the PLQY and the stability of the resulting material. Moreover, the introduction of b-PEI promotes a partial phase conversion from CsPbBr₃ to CsPb₂Br₅ to obtain CsPbBr₃/CsPb₂Br₅ nanocrystals with a core-shell-like structure. As-prepared PNCs solutions are directly processable as inks, while their PLQY drops only slightly from 75% in colloidal solution to 65% in films. Moreover, the final PNC-polymer film exhibits excellent stability against water, heat, and ultraviolet light irradiation. These superior properties allowed us to fabricate a proof of concept thin film OLED with h-PMMA/b-PEI-stabilized PNCs as an easily processable, narrowly emitting color conversion composite material.

High Photocatalytic Activity under Visible Light for a New Morphology of Bi2WO6 Microcrystals

In this work, a new morphology was obtained for bismuth tungstate (Bi2WO6-glyc) using a hydrothermal method with the addition of glycerol as a surfactant. In order to compare, the bismuth tungstate without glycerol as the surfactant, i.e., Bi2WO6, was synthesized. Structural characterization by XRD and Rietveld refinement confirmed the orthorhombic structure as a single phase for all samples with high crystallinity. All active modes in Raman spectroscopy for the orthorhombic phase of bismuth tungstate were confirmed in agreement with XRD analysis. N2 adsorption/desorption and size pore distribution confirmed the high surface area (85.7 m2/g) for Bi2WO6-glyc when compared with Bi2WO6 (8.5 m2/g). The optical band gap by diffuse reflectance was 2.78 eV and 2.88 eV for Bi2WO6-glyc and Bi2WO6, respectively. SEM images confirmed the different morphology for these materials, and microstructures with cheese crisp were observed for Bi2WO6-glyc (cheese crisp). On the other hand, flower-like microcrystals were confirmed for Bi2WO6 sample. The photocatalytic performance of Bi2WO6-glyc (94.2%) in the photodegradation of rhodamine B (RhB) dye solutions at 60 min was more expressive than Bi2WO6 (81.3%) and photolysis (8.2%) at 90 min.

Hierarchical Nanostructured Photocatalysts for CO2 Photoreduction

Practical implementation of CO2 photoreduction technologies requires low-cost, highly efficient, and robust photocatalysts. High surface area photocatalysts are notable in that they offer abundant active sites and enhanced light harvesting. Here we summarize the progress in CO2 photoreduction with respect to synthesis and application of hierarchical nanostructured photocatalysts.

Positive effect of Fe3+ ions on Bi2WO6, Bi2MoO6 and BiVO4 photocatalysis for phenol oxidation under visible light

Catalyst activity is notably enhanced on simple addition of Fe³⁺ ions. The reaction is fast initially and then becomes slow, but the formation of reactive species is accelerated even in the slow process.

Synthesis of Bi-deficient monolayered Bi2WO6 nanosheets with enhanced photocatalytic activity under visible light irradiation

The strong protonated hydroxyl groups around Bi vacancies could efficiently promote the separation of photoexcited electron–hole pairs.

Developmental trends in CO2 methanation using various catalysts

Co₂ methanation-two edged sword to counter global warming and energy crisis.

Surfactant-free hydrothermal synthesis of hierarchical flower-like Bi2WO6 mesosphere nanostructures with excellent visible-light photocatalytic activity

Hierarchical flower-like Bi₂WO₆ mesosphere nanostructures self-assembled with nanosheets were synthesized by hydrothermal treatment of an aqueous suspension of Bi(NO₃)₃·5H₂O and Na₂WO₄·2H₂O without surfactants or mineralizers.

Compositing Two-Dimensional Materials with TiO2 for Photocatalysis

Energy shortage and environmental pollution problems boost in recent years. Photocatalytic technology is one of the most effective ways to produce clean energy—hydrogen and degrade pollutants under moderate conditions and thus attracts considerable attentions. TiO2 is considered one of the best photocatalysts because of its well-behaved photo-corrosion resistance and catalytic activity. However, the traditional TiO2 photocatalyst suffers from limitations of ineffective use of sunlight and rapid carrier recombination rate, which severely suppress its applications in photocatalysis. Surface modification and hybridization of TiO2 has been developed as an effective method to improve its photocatalysis activity. Due to superior physical and chemical properties such as high surface area, suitable bandgap, structural stability and high charge mobility, two-dimensional (2D) material is an ideal modifier composited with TiO2 to achieve enhanced photocatalysis process. In this review, we summarized the preparation methods of 2D material/TiO2 hybrid and drilled down into the role of 2D materials in photocatalysis activities.