查找使用阿拉丁产品的科研文献

Nanotube array-like WO3/W photoanode fabricated by electrochemical anodization for photoelectrocatalytic overall water splitting

Lingfeng Li,Xiaolong Zhao,Donglai Pan,Guisheng Li

Photoactive WO 3 is attractive as a photocatalyst for green energy evolution through water splitting. In the present work, an electrochemical anodic oxidation method was used to fabricate a photo-responsive nanotube array-like WO 3 /W (NA-WO 3 /W) photoanode from W foil as a precursor. Compared with a reference commercial WO 3 /W electrode, the NA-WO 3 /W photoanode exhibited enhanced and stable photoelectrocatalytic (PEC) activity for visible-light-driven water splitting with a typical H 2 /O 2 stoichiometric ratio of 2:1 and quantum efficiency of approximately 5.23% under visible-light irradiation from a light-emitting diode ( λ = 420 nm, 15 mW/cm 2 ). The greatly enhanced PEC performance of the NA-WO 3 /Wphotoanode was attributed to its fast electron–hole separation rate, which resulted from the one-dimensional nanotube array-like structure, high crystallinity of monoclinic WO 3 , and strong interaction between WO 3 and W foil. This work paves the way to a facile route to prepare highly active photoelectrodes for solar light transfer to chemical energy .

Photoinduced Ce–MoS2/WO3 nanocomposites with enhanced photodynamic and enzyme-like activity for rapid sterilization

Junli Liu,Wenxia Cheng,Kaitao Zhang,Hui Liu

Bacterial infections is a serious threat to our health. Thus, there is an urgent need to develop a new effective antibacterial agent. In this work, we developed a novel and environmentally friendly Ce–MoS 2 /WO 3 nanocomposite antimicrobial agent with excellent antimicrobial effect and the antimicrobial efficiency against E. coli reached to 97.8% under visible light irradiation. Electron paramagnetic resonance (EPR) spectra showed that the large amounts of superoxide anion radical (•O 2 − ) and hydroxyl radical (•OH) were generated by the nanocomposites under light excitation, which were the main active substances causing oxidative damage for bacteria. Simultaneously, the photothermal curve and peroxidase activity test of Ce–MoS 2 /WO 3 nanocomposites confirmed it has the excellent photothermal effect and enhanced enzyme-like activity, which further assisted in antibacterial effects. Ce doping enlarges the layer spacing of MoS 2 and forms lattice dislocations and distortions, effectively increasing the defect sites at the layer edges, and the coupling of Ce–MoS 2 and WO 3 to construct heterojunctions reduces the charge separation rate, which further improves the photocatalytic antibacterial performance and enzyme-like antibacterial activity of Ce–MoS 2 /WO 3 nanocomposites.

Lamellar WO3/AgI S-scheme heterojunction for superior visible light driven photocatalytic degradation of ciprofloxacin

Junchang Liu,Minghui Zhu,Weijie Yuan,Guoying Yang,Chen Zhang,Huayang Zhang,Dafeng Zhang,Peiqing Cai,Xipeng Pu

A unique lamellar WO 3 /AgI S-scheme heterojunction is constructed via integrated hydrothermal and coprecipitation methods. Optimized WO 3 /AgI composite shows significantly enhanced photocatalytic ciprofloxacin (CIP) degradation under visible light irradiation, achieving a removal rate of 53.4 % within 3 h, which is about 7.63 and 1.56 times superior than those of pristine WO 3 and AgI, respectively. The characterizations, experiment results and Density Functional Theoretical (DFT) calculation results confirm the enhanced light absorption, well-aligned straddling band structures and reasonable formation of S-scheme heterojunction with efficient photogenerated carriers transfer between WO 3 and AgI. Moreover, O 2 − and h + are identified as the main active species, with O 2 − plays a dominant role in WO 3 /AgI during the photocatalytic degradation of CIP. This work elucidates a possible approach to develop photocatalysts with a high antibiotic removal efficiency through a higher reducing ability and stronger oxidizing ability of S-scheme heterojunction by reasonable structure configuration.

Synergistic Spatial Confining Effect and O Vacancy in WO3 Hollow Sphere for Enhanced N2 Reduction

Yuzhou Xia,Xinghe Xia,Shuying Zhu,Ruowen Liang,Guiyang Yan,Feng Chen,Xuxu Wang

Visible-light-driven N2reduction into NH3in pure H2O provides an energy-saving alternative to the Haber–Bosch process for ammonia synthesizing. However, the thermodynamic stability of N≡N and low water solubility of N2remain the key bottlenecks. Here, we propose a solution by developing a WO3−xhollow sphere with oxygen vacancies. Experimental analysis reveals that the hollow sphere structure greatly promotes the enrichment of N2molecules in the inner cavity and facilitates the chemisorption of N2onto WO3−x-HS. The outer layer’s thin shell facilitates the photogenerated charge transfer and the full exposure of O vacancies as active sites. O vacancies exposed on the surface accelerate the activation of N≡N triple bonds. As such, the optimized catalyst shows a NH3generation rate of 140.08 μmol g−1h−1, which is 7.94 times higher than the counterpart WO3-bulk.Keywords:WO3;hollow sphere;O defect;N2reduction;photocatalysis

In Situ Growth of Oxygen Defect-Rich Ultrathin WO3 Nanosheets for Ultrafast Recovery NO2 Sensors

Yanghai Gui,Linlin Qian,Kuan Tian,Jintao Wu,Yuansheng Tu,Xiaoyun Qin,Xiaomei Qin

Z-scheme heterojunction ZnS/WO3 composite: Photocatalytic reduction of uranium and band gap regulation mechanism

Ning Liu,Rumin Li,Jiahui Zhu,Qi Liu,Rongrong Chen,Jing Yu,Ying Li,Hongsen Zhang,Jun Wang

In the present research, ZnS/WO 3 composites were prepared by coprecipitation method to construct the Z-scheme heterojunction photocatalyst with high efficiency electron separation for the photocatalytic reduction of U(VI). Compared with WO 3 and ZnS, the visible light absorption, photoreduction ability and photocatalytic activity of ZnS/WO 3 composites were improved. The ZnS/WO 3 composites show higher photoreduction U(VI) performance under visible light irradiation with the maximum extraction capacity of U(VI) at 1.52 g g −1 . The ZnS/WO 3 composites exhibit high uranium reduction ability under natural light with removal efficiency reaching 93.4 %. In-situ monitoring experiments and DFT calculations were designed to explore the mechanism and pathway of photoelectron transfer in the reduction process from U(VI) to U(IV). The results show that ZnS/WO 3 has an internal electric field to form a Z-scheme electron transfer , and uranium reduction is a dual-electron transfer pathway. In addition, the band gap regulation mechanism of binary composite semiconductor materials is deeply discussed.

Core-shell catalyst WO3@mSiO2-SO3H interfacial synergy catalyzed the preparation of furfural from xylose

Renjie Ji,Long Jiang,Defu Yin,Fanglin Lv,Shitao Yu,Lu Li,Shiwei Liu,Qiong Wu,Yue Liu

A core-shell biacid catalyst WO 3 @mSiO 2 -SO 3 H was prepared. Through the core-shell structure, an interface with internal and external spatial relationship was formed, which was used to synergistic catalyze the preparation of furfural from xylose . And the conversion of xylose was as high as 98.7% and the furfural yield was 70.1% at 170°C for 4 h in water-toluene mixture (1:2 v/v%). The research provided a case for the preparation of furfural from xylose catalyzed by sulfonated core-shell catalyst and provided more application prospects for core-shell catalysts in biomass conversion .

Improving the production of furfural from cellulose catalytic pyrolysis using WO3/γ-Al2O3 composite oxides

Koïta Djakaria,Ziyue Tang,Jingai Shao,Xu Chen,Haoyu Xiao,Joseph Smith,Haiping Yang,Hanping Chen

Furfural is one of the top valuable building block chemicals, the selective production of furfural from biomass has attracted increasing concerns in recent years. In this work, a novel method for the selective production of furfural through cellulose catalytic pyrolysis with WO 3 /γ-Al 2 O 3 was reported, and the synergistic effect between γ-Al 2 O 3 and WO 3 was explored. Compared with cellulose pyrolysis alone, the addition of γ-Al 2 O 3 improved the selectivity of furans and greatly inhibited the formation of sugars; while, WO 3 addition promoted the formation of levoglucosenone . When (20–40%) WO 3 /γ-Al 2 O 3 were added, the amount of sugars was further reduced, and the yields of furans (furfural and 2-methylfuran, in particular) were further increased at the same time. Under the optimum conditions (temperature = 600 °C, residence time = 15 s, and catalyst to cellulose mass ratio of 4), 30%WO 3 /γ-Al 2 O 3 showed the best performance, and the selectivity and yield of furfural were improved by nearly 100% and 300%, respectively, as compared with cellulose pyrolysis alone. In addition, compared with γ-Al 2 O 3 , the addition of 30%WO 3 /γ-Al 2 O 3 further increased the yield of furfural and 2-methylfuran to about 50% and 200%, respectively. The high selectivity and yields of furans with WO 3 /γ-Al 2 O 3 addition might be due to that WO 3 crystals in the composite promote the formation of levoglucosenone, which is further converted to additional furans through the Lewis acid sites of γ-Al 2 O 3 . The study may provide some meaningful advices for improving the production of furfural from green catalytic pyrolysis of cellulose.

Oxidative Cleavage of Methyl Epoxystearate over Al-MCM-41-Assisted WO3∙nH2O for Aldehyde Products

Kainan Xing,Minghe Cao,Qinkai Zhu,Haojie Yin,Meizhen Lu,Jianbing Ji

Vegetable oils and their derivatives are of great interest because of their abundance and renewability. This paper prepares nonanal (N) and methyl 9-oxonanoate (M) from methyl epoxystearate (ME) with WO 3 ∙0.33H 2 O, WO 3 ∙H 2 O, and WO 3 ∙2H 2 O as catalysts and H 2 O 2 as the oxidant without the use of organic solvent. The reaction temperature, catalyst amount, H 2 O 2 amount, and reaction time effects on ME conversion and N/M yield are investigated. The results show that WO 3 ∙H 2 O has the best catalytic performance. The optimal reaction conditions are: reaction temperature 60 °C, reaction time 40 min, ME/H 2 O 2 /WO 3 ∙H 2 O molar ratio 1/1.2/0.4, under which the ME conversion and N/M yield reach 95% and 70%, respectively. WO 3 ∙ n H 2 O reacts with H 2 O 2 to form soluble tungsten anions, resulting in severe tungsten loss. Al-MCM-41 materials with different silicon to aluminum molar ratios are added to the reaction system as adsorbents to recover the catalyst by effective adsorption of tungsten anions. The adsorption performance improves as the Si/Al ratio decreases, however, the ME conversion and N/M yield decrease. Thus, 50 is the most suitable Si/Al ratio. The ME conversion and N/M yield can still reach 90% and 60% after four times of use. Practical applications : The nonanal has a natural fragrance and can be used in the cosmetic industry as well as in the preparation of bio-based surfactants. The methyl 9-oxonanoate can be converted into polymer monomers by hydrogenation or amination. The results show that WO 3 ∙ n H 2 O has good catalytic activity, and a satisfying yield of aldehyde products is obtained under mild reaction conditions.

Construction of highly active WO3/TpPa-1-COF S-scheme heterojunction toward photocatalytic H2 generation

Long Sun,Lingling Li,Jiajie Fan,Quanlong Xu,Dekun Ma

The rapid charge recombination and low surface reaction kinetics are the two major constraints to the photocatalytic performance of covalent organic frameworks (COFs). To accelerate the charge separation behavior, TpPa-1-COF is decorated with WO 3 via an in-situ growth approach, and the resultant WO 3 /TpPa-1-COF composites show significantly improved photocatalytic performance. Especially, when the WO 3 loading arrives at 3 wt%, 3%WO 3 /TpPa-1-COF exhibits the maximum photocatalytic H 2 evolution rate of 19.89 mmol g −1 h −1 , which is approximately 4.8 times higher than that of pure TpPa-1-COF. The apparent quantum efficiency (AQE) of 3%WO 3 /TpPa-1-COF at 420 nm is detected to be 12.4%. X-ray photoelectron spectroscopy (XPS) characterization confirms the formation of internal electric field between WO 3 and TpPa-1-CF, which can drive the photogenerated charge carrier diffusion in S-scheme mode. As a result, WO 3 /TpPa-1-COF composite possesses high charge separation efficiency and strong redox ability, which is further supported by the photoelectrochemical results, thus benefiting the photocatalysis process. This work provides a rational strategy to modify COFs in photocatalytic water splitting.

Monoclinic WO3 nanosheets-carbon nanotubes nanocomposite based electrochemical sensor for sensitive detection of bisphenol A

Yang Zhou,Xiaoyan She,Qiong Wu,Jiangrong Xiao,Tianyou Peng

A novel and sensitive electrochemical sensor based on monoclinic tungsten trioxide (WO 3 ) nanosheets-carbon nanotubes nanocomposite (WO 3 -CNT) modified glass carbon electrode (GCE) is developed for the direct detection of endocrine disruptor bisphenol A (BPA) in textile sample for the first time. The electrochemical behavior of BPA on the resultant WO 3 -CNT/GCE sensor is investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and chronocoulometry (CC). Under the optimized conditions, the proposed sensor can be adopted to the quantification of BPA using differential pulse voltammetry (DPV), and the electro-oxidation peak current is proportional to the BPA concentration in the range of 0.03–3.0 μM and 3.0–100 μM with a correlation coefficient of 0.9993 and 0.9992, respectively. Moreover, the proposed sensor with a detection limit of 16.3 nM (S/N = 3) exhibits good reproducibility, selectivity and stability, and can be successfully applied to detect the BPA concentrations in real samples (textile, plastic and tap water) with satisfactory recovery (99.4%-110.1%). The present strategy on the hybridization of CNTs and WO 3 enables more opportunities for the electrochemical detection of BPA in the practical applications.

Rapid switching of a Pt-free photovoltachromic device based on WO3 using PProDOT-Me2 catalyst

Kai Sheng,Mahmoud A. Khalifa,Zitao Wang,Jianming Zheng,Chunye Xu

Developing a low-cost and efficient Photovoltachromic Device (PVCD) can address the requirements of energy-harvesting smart windows . In this work, low-cost poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me 2 ) is presented for replacing expensive Pt and achieving a WO 3 -based PVCD with rapid bleaching speed. The device consists of the proposed WO 3 /PProDOT-Me 2 electrode, an electrolyte containing I − /I 3 − redox couple , and dye-sensitized TiO 2 photoanode. The PVCD changes state between colored and bleached by simply altering the open and short circuit of the device. The PVCD achieves high optical contrast of 45.1% at 680 nm with a fast bleaching time of 15.5 s, coloring time of 3.6 s, and cycling stability over 200 cycles. These unique characteristics result from the PProDOT-Me 2 could help accelerate the electrochromic process of WO 3 and fast transferring charges to the electrolyte that enhances photovoltaic performance . The accelerating mechanism is analyzed and the related experimental evaluations are executed. This study reveals promising prospects of the proposed WO 3 -PProDOT-Me 2 electrode for low-cost PVCD.