查找使用阿拉丁产品的科研文献

Simple fabrication of Z-scheme MgIn2S4/Bi2WO6 hierarchical heterostructures for enhancing photocatalytic reduction of Cr(VI)

Jiaqi Dong,Jianqiang Hu,Anyu Liu,Jiale He,Qingling Huang,Yanru Zeng,Wenjing Gao,Zhen Yang,Yongcai Zhang,Yong Zhou,Zhigang Zou

Direct Z-scheme MgIn2S4/Bi2WO6 hierarchical heterostructures were simply fabricated via immobilising MgIn2S4 nanoflakes onto the surface of Bi2WO6 hierarchical nanosheet-like structures towards photocatalytic reduction of Cr(VI). The analyses of the energy band structure, UPS tests and DMPO-ESR spin-trap experiments confirm that the intimate MgIn2S4/Bi2WO6 heterointerface allows an efficient Z-scheme interfacial charge migration route between MgIn2S4 and Bi2WO6, leading to higher redox ability of photoexcited carriers, and thus favours the separation of photoexcited carriers, proved by the results of PL spectroscopy, photoluminescence decay traces, transient photocurrent densities and EIS. In addition, the MgIn2S4/Bi2WO6 heterostructures also exhibit obviously enhanced ultraviolet-visible-light absorption according to UV-vis DRS analysis, and can generate more electron–hole pairs under UV-visible light illumination, effectively improving the photocatalytic activity. Therefore, because of their synergistic effects, all the MgIn2S4/Bi2WO6 hierarchical heterostructures show distinctly improved photoreduction activities for Cr(VI), compared with pure Bi2WO6. The optimal hybrid (MIS/BWO-0.35) displays nearly 100% Cr(VI) reduction into Cr(III) after 40 min of simulated sunlight illumination, which is better than the majority of the reported Bi2WO6 and other semiconductor photocatalysts before. Its reaction rate constant for the photoreduction of Cr(VI) (0.1063 min−1) is about 4.5 times higher than that of the pristine Bi2WO6 (0.0237 min−1). This work provides a valid approach for developing efficient Z-scheme photocatalytic materials in removing Cr(VI).

Black/red phosphorus Z-scheme hybrid with novel photosynthesis-inspired electrolyte additives for enhanced photoelectrochemical activity

Gengcheng Liao,Hui Qiao,Zongyu Huang,Siwei Luo,Yuan Ji,Yundan Liu,Xiang Qi

Designing a Z-scheme heterojunction is of great significance to achieve high separation of photogenerated carriers and strong photo-redox properties of two semiconductor materials . In photosynthesis, the effects of photocatalytic electrolytes (adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH)) on chemical energy has attracted numerous interests. In this case, developing photocatalytic electrolytes with more active site and efficient charge extraction and separation would be beneficial for superior photocatalytic activity in Z-scheme system. Herein, we synthesized a Black/Red (BP/RP) phosphorus Z-scheme hybrid via a feasible two-steps sonochemical method, and the adding photocatalytic electrolytes ATP and NADPH in KOH solution endow the system with new vitality in photocatalysis . Consequently, photoelectrochemical (PEC) tests demonstrated the as-prepared BP/RP Z-scheme hybrid exhibits enhanced photocurrent of 9 μA/cm 2 at 0.5 V compared to the sole RP, while adding NADPH and ATP, the photocurrent of BP/RP Z-scheme hybrid shows dramatic increment of 30 μA cm −2  at a bias potential of 0.6 V. The improved photocatalytic activity is ascribed to the abundant active sites, higher carrier mobility of the BP/RP Z-scheme system, as well as the efficient photogenerated carrier separation and the prolonged lifetime of photocatalytic electrolytes. This work demonstrated the photocatalytic electrolytes can meet the unity of coordination and efficiency of achieving efficient PEC catalytic in the Z-Scheme system, and provides positive ideas for the possibility and superiority for other 2D materials in the field of ultrafast Photonics , photodetectors , etc.

Enhanced visible-light-driven photocatalytic activity of Bi2WO6-BiSI Z-scheme heterojunction photocatalysts for tetracycline degradation

Rui Zhang,Kunlin Zeng,Tongqing Zhang

Direct Z-scheme α-MnO2@MnIn2S4 hierarchical photocatalysts with atomically defined junctions for improved photocatalytic activities

Min Zhang,Muhammad Arif,Yuxiang Hua,Bo Qiu,Yue Mao,Xiaoheng Liu

The use of semiconductor photocatalysts to generate electrons with efficient reducing capability for organic photoreduction synthesis and the removal of harmful substances has become a hotspot in the field of green chemistry research. In this work, α-MnO2 nanocubes and α-MnO2@MnIn2S4 hybrid photocatalysts with a core–shell structure were synthesized successively by a two-step method. XRD and XPS verified the coexistence of the two substances (α-MnO2 and MnIn2S4) in hybrid systems. According to the SEM and TEM characterization, it is clearly seen that MnIn2S4 nanosheets grow on α-MnO2 nanocubes to form a hierarchical structure. Furthermore, HRTEM showed that the interface contact between α-MnO2 and MnIn2S4 resulted in an atomically defined junction. The photocatalytic performance of the composite catalyst was evaluated by reducing 4-nitroaniline to 4-phenylenediamine and Cr(VI) to Cr(III), respectively. The results show that the catalytic activity of the composite material is effectively improved compared to that of the single components. The Z-scheme electron transport mechanism was proved by ultraviolet-visible diffuse reflectance spectroscopy, valence band XPS, energy band structure calculation and active species detection experiments. The constructed Z-scheme hierarchical α-MnO2@MnIn2S4 system with an atomically defined junction can improve the redox performance of semiconductors for organic synthesis and environmental remediation.

Construction of direct Z-scheme WO3/ZnS heterojunction to enhance the photocatalytic degradation of tetracycline antibiotic

J.C. Murillo-Sierra,A. Hernández-Ramírez,Zong-Yan Zhao,Angel Martínez-Hernández,M.A. Gracia-Pinilla

Heterogeneous photocatalysis has been considered as a green and sustainable alternative for water decontamination where the key step is the nanomaterials design to enhance the photocatalytic process. Therefore, in this study the photocatalytic degradation of an emerging contaminant as the tetracycline antibiotic in aqueous solution, was investigated under UV–Vis irradiation by using the WO 3 /ZnS photocatalyst. The coupled catalyst was synthesized by hydrothermal method and by varying the WO 3 weight ratio (5, 10 and 20 wt%) with respect to the ZnS. The WO 3 /ZnS photoactivity for tetracycline degradation was greatly enhanced when both semiconductors were coupled to form a highly efficient direct Z-scheme. The highest degradation percentage was reached using the catalyst t WO 3 (5%)/ZnS, which completely degraded the pollutant within 90 min, and the determination of total organic carbon (TOC) removal indicated a high mineralization degree. Photoelectrochemical studies showed that WO 3 (5%)/ZnS exhibited the highest separation of e − / h + pairs and the highest transfer efficiency. The improvement of the electron-hole separation in combination with the band alignment analysis, explained the intrinsic mechanism which corresponded to the direct Z-scheme photocatalytic system.

Effective inactivation of Microcystis aeruginosa by a novel Z-scheme composite photocatalyst under visible light irradiation

Dongxu Wang,Yanhui Ao,Peifang Wang

Microcystis aeruginosa is one of the most famous harmful algae. In this work, Z -scheme g-C 3 N 4 -MoO 3 (Mo-CN) composite photocatalysts were successfully synthesized to alleviate the algae pollution. The obtained composites exhibited excellent performance for the inactivation of M. aeruginosa . The optimal photocatalysts (15Mo-CN) achieved a removal efficiency of 97% for the algal cells after 3 h visible light irradiation, which was attributed to their remarkable surface properties and ingenious structure design. The physiological status of Microcystis aeruginosa were evaluated by the chlorophyll a (chla), relative electron transport rate (rETR) and maximum photochemical efficiency (Fv/Fm), and all of them decreased in different degrees. Furthermore, the as-prepared photocatalysts also show a certain activity for the removal of leaked macromolecule organic compounds during the process of algal cells inactivation. Finally, a possible mechanism on the photocatalytic inactivation of algal cells by the Z -scheme photocatalysts was deduced based on the experimental and characterization results. We believe this study would provide new insights into the development of promising technology and basic theory for remediation of algae pollution.

Design and performance of a novel direct Z-scheme NiGa2O4/CeO2 nanocomposite with enhanced sonocatalytic activity

Guowei Wang,Xue Ma,Jue Liu,Lifan Qin,Bing Li,Yuanan Hu,Hefa Cheng

A novel direct Z-scheme NiGa 2 O 4 /CeO 2 nanocomposite was designed and prepared via simple sol-hydrothermal and calcination methods, and its sonocatalytic activity was tested by studying the degradation of a model antimicrobial agent, malachite green (MG), under ultrasonic irradiation. Near complete (96.2%) degradation of MG (at 10 mg/L) could be achieved by the NiGa 2 O 4 /CeO 2 nanocomposite (at 1.0 g/L) after ultrasonic irradiation (40 kHz, 300 W) for 60 min at 25 °C. Under the same conditions, only 51.2 and 72.0% of the MG degraded in the presence of NiGa 2 O 4 and CeO 2 (at 1.0 g/L), respectively. These results demonstrate that the direct Z-scheme NiGa 2 O 4 /CeO 2 nanocomposite has excellent sonocatalytic activity, which is attributed to the matching band-gaps between NiGa 2 O 4 and CeO 2 . The sonocatalytic activity of NiGa 2 O 4 /CeO 2 nanocomposite decreased by 17% after four cycles of reuse, which is indicative of relatively good reusability. Scavenging experiments revealed that sonocatalytic degradation of MG results from the combined action of hydroxyl radicals ( OH) and holes (h + ), with the latter having a greater contribution. The pathways and mechanism of MG degradation were proposed based on the degradation intermediates detected. The results demonstrate that the prepared direct Z-scheme NiGa 2 O 4 /CeO 2 nanocomposite worked as designed and exhibited high and stable sonocatalytic activity during MG degradation, and could thus serve as a promising candidate in sonocatalytic treatment of other organic pollutants in wastewaters. The findings also provide new insights on the mechanism of sonocatalytic degradation and the design of efficient Z-scheme sonocatalysts.

Direct and indirect Z-scheme heterostructure-coupled photosystem enabling cooperation of CO2 reduction and H2O oxidation

Wang Ying,Shang Xiaotong,Shen Jinni,Zhang Zizhong,Wang Debao,Lin Jinjin,Wu Jeffrey C. S.,Fu Xianzhi,Wang Xuxu,Li Can

The stoichiometric photocatalytic reaction of CO 2 with H 2 O is one of the great challenges in photocatalysis. Here, we construct a Cu 2 O-Pt/SiC/IrO x composite by a controlled photodeposition and then an artificial photosynthetic system with Nafion membrane as diaphragm separating reduction and oxidation half-reactions. The artificial system exhibits excellent photocatalytic performance for CO 2 reduction to HCOOH and H 2 O oxidation to O 2 under visible light irradiation. The yields of HCOOH and O 2 meet almost stoichiometric ratio and are as high as 896.7 and 440.7 μmol g −1  h −1 , respectively. The high efficiencies of CO 2 reduction and H 2 O oxidation in the artificial system are attributed to both the direct Z-scheme electronic structure of Cu 2 O-Pt/SiC/IrO x and the indirect Z-scheme spatially separated reduction and oxidation units, which greatly prolong lifetime of photogenerated electrons and holes and prevent the backward reaction of products. This work provides an effective and feasible strategy to increase the efficiency of artificial photosynthesis.

Oxygen defects engineered CdS/Bi2O2.33 direct Z-Scheme heterojunction for highly sensitive photoelectrochemical assay of Hg2+

Shuo Wu,Yan Zhao,Xunxun Deng,Xinlan Yang,Xiuyun Wang,Yanqiu Zhao

This work demonstrates that the photoelectrochemical response of the CdS/Bi 2 O 2.33 direct Z-scheme heterojunction, synthesized by in situ deposition of CdS nanocrystals on the defect engineered Bi 2 O 2.33 , can be modulated by oxygen defect concentration. The appropriate oxygen defects not only increase the visible light absorption, provide active reaction sites to enhance PEC activity, but also promote the separation of carriers. The formation of CdS/Bi 2 O 2.33 direct Z-scheme heterojunction further improves these properties by extending the visible light absorption and promoting separation and transport of carriers, but avoids the usage of noble metal nanoparticles as electron transfer mediators, thus has a low cost and easy fabrication technology. The CdS/Bi 2 O 2.33 direct Z-scheme junction shows significantly improved photocurrent response as compared with those containing less oxygen defects, and is applied as a photoelectrochemical assay platform for Hg 2+ . The specific interaction between Hg 2+ and the S 2− in CdS significantly quenches the photocurrent response of the CdS/Bi 2 O 2.33 due to the formation of HgS. The photocurrent decrease is linear to the concentration of Hg 2+ in the range from 10 −11 to 10 −6  g/mL, with the limit of detection of 3.2 pg/mL. High accuracy and good reproducibility are realized in the real sample analysis of urine, river water, and sea water. The integration of oxygen defect engineering and direct Z-scheme electron transport principle provides a new avenue for fabricating high performance photoelectrochemical materials, which can be further combined with bio-recognition strategy for the ultrasensitive detection of biological molecules.

A Novel Organic/Inorganic Dual Z-Scheme Photocatalyst with Visible-Light Response for Organic Pollutants Degradation

Taoming Yu,Doudou Wang,Lili Li,Wenjing Song,Xuan Pang,Ce Liang

The design of highly efficient organic/inorganic photocatalysts with visible-light response has attracted great attention for the removal of organic pollutants. In this work, the polyacrylonitrile (PAN) worked as the matrix polymer, while polyaniline (PANI) and Sb2S3–ZnO were used as organic/inorganic photocatalysts. The heterojunction PAN/PANI–Sb2S3–ZnO photocatalyst was prepared using electrospinning and surface ultrasound. PAN/PANI–Sb2S3–ZnO exhibited an excellent visible-light absorption intensity in the wavelength range of 400–700 nm. The maximum removal efficiencies of PAN/PANI–Sb2S3–ZnO for four organic dyes were all greater than 99%. The mechanism study showed that a dual Z-scheme could be constructed ingeniously because of the well-matched bandgaps between organic and inorganic components in the photocatalyst, which achieved efficient separation of photogenerated carriers and reserved photogenerated electrons (e−) and holes (h+) with strong redox ability. The active species •OH and •O2−played an important role in the photocatalytic process. The composite photocatalyst also had excellent stability and reusability. This work suggested a pathway for designing novel organic/inorganic composite photocatalysts with visible-light response.Keywords:photocatalyst;Sb2S3;PANI;ZnO

Photocatalytic degradation of tetrabromobisphenol A by Z-scheme WO3/ZnIn2S4 heterojunction: Efficiency, mechanism and toxicity evaluation

Bin Xu,Zhiquan An,Minjie Li,Bihong Zhang,Liang-Hong Guo

Occurrence of brominated flame retardants especially tetrabromobisphenol A (TBBPA) in water bodies poses a serious threat to aquatic ecosystems . Heterogeneous photocatalysis is a versatile technology that can efficiently degrade organic contaminants . However, existing studies on photocatalytic degradation of TBBPA are all achieved under intense light irradiation and high initial concentrations of TBBPA, which are far from real environmental conditions and not conducive to practical application. In this study, series of Z-scheme heterojunctions of WO 3 /ZnIn 2 S 4 photocatalysts were prepared and used for the high-efficiency photocatalytic degradation of TBBPA at lower light irradiation intensity (100 W) and lower TBBPA concentration (5.4 mg/L). Among them, WO 3 /ZnIn 2 S 4 -3 (molar ratio of 1:3) exhibited the highest photocatalytic activity due to the formation of Z-Scheme heterojunction which effectively facilitated the separation of photogenerated charges and endowed WO 3 /ZnIn 2 S 4 -3 higher redox ability. Thus, under light illumination, 91.6% degradation of TBBPA was achieved at an initial pH of 8.0 within 150 min, with a pseudo-first-order rate constant of 0.01572 min −1 . Electron spin resonance spectroscopy and radical scavenger experiments confirmed that ·O 2 − radicals were the primary reactive oxygen species driving the TBBPA degradation. By applying LC-MS/MS, the degradation products were identified and possible degradation pathways were proposed. Finally, potential toxicity for PBBPA and generated intermediates were evaluated using luminescent bacteria, which revealed the toxicity of PBBPA was reduced effectively during the photocatalytic degradation process. Overall, the Z-scheme WO 3 /ZnIn 2 S 4 photocatalyst provides a promising way for the application of photocatalytic technology in actual wastewater treatment .

Selective removal of sulfamethoxazole by a novel double Z-scheme photocatalyst: Preferential recognition and degradation mechanism

Jing-Yan Zhang,Jie Ding,Lu-Ming Liu,Rui Wu,Lan Ding,Jun-Qiu Jiang,Ji-Wei Pang,Yan Li,Nan-Qi Ren,Shan-Shan Yang

Sulfamethoxazole (SMX) is a significant environmental concern due to its adverse effects and ecological risks. SMX elimination in aquatic environments via photocatalysis presents a viable solution, given its high oxidation potential. However, such a solution remains controversial, primarily due to a lack of selectivity. Here we introduce a molecularly imprinted TiO 2 @Fe 2 O 3 @g-C 3 N 4 (MFTC) photocatalyst designed for the selective degradation of SMX. To assess MFTC's selectivity, we applied it to degrade synthetic wastewater containing SMX alongside interfering species sulfadiazine (SDZ), ibuprofen (IBU), and bisphenol A (BPA). The results demonstrated a selective degradation efficiency rate of 96.8%, nearly twice that of competing pollutants. The molecularly imprinted sites within the catalyst played a crucial role by selectively capturing SMX and enhancing its adsorption, thereby improving catalytic efficiency. The degradation process involved •OH and •O 2 − free radicals, with a newly proposed double Z-scheme mechanism and potential pathway for SMX degradation by the MFTC photocatalytic system. This study enriches the application of photocatalysis using molecularly imprinted nanocomposite materials for treating complex pollutant mixtures in water.