APPLIED SURFACE SCIENCE
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2020
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IF 6.182
Di Zhang,Juanyuan Hao,Peng Wan,Dan Zhang,Quan Sun,Zongjun Liu,Fei Li,Haitao Fang,You Wang
The rapid recombination and poor redox capability of photoinduced charge carriers seriously impede the photocatalytic activity . Herein, a direct Z-scheme photocatalyst was fabricated by selectively depositing Ag 6 Si 2 O 7 nanoparticles (NPs) on the {0 4 0} facets of BiVO 4 . Owing to the facet-dependent band structure of BiVO 4 , the photoinduced electrons and holes can be pre-separated upon photoillumination and transfer to {0 4 0} and {1 1 0} facets of BiVO 4 , respectively. A rapid combination of the separated electrons at the {0 4 0} facets of BiVO 4 with holes of the Ag 6 Si 2 O 7 NPs then takes place triggering a direct Z-scheme photocatalysis. Such a charge pre-separation triggered by the faceted BiVO 4 , together with Z-scheme at the interface warrants not only effective photoinduced charge separation but also excellent redox capability owing to the increased redox potential. The photocatalytic rate constant of the optimum BiVO 4 {0 4 0}/Ag 6 Si 2 O 7 heterostructure is 28.2 and 17.2 times higher than those of pristine BiVO 4 and Ag 6 Si 2 O 7 , respectively. This study offers a new insight for constructing direct Z-scheme photocatalysts with high degradation efficiency based on facet-controlled crystals.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
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2024
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IF 4.9
Miaomiao Song,Weihua Ma
Increasing attention has been directed towards oxidase mimics due to their catalytic ability toward enzyme substrates in the absence of H 2 O 2 , offering great colorimetric sensing potential in assays and diagnostics. However, slow electron-transfer and unstable absorbance over time often lead to unsatisfactory enzymatic reaction rates and unreliable readouts, significantly reducing detection efficiency and accuracy. Herein, we report on an Ag 6 Si 2 O 7 nanozyme utilizing 3,3′,5,5′-tetramethylbenzidine (TMB) as a chromogenic substrate, demonstrating excellent oxidase-like activity and long-term stable colorimetric signals. Experimental results reveal that the excellent catalytic kinetics of Ag 6 Si 2 O 7 (K m = 0.197 mM, Vmax = 5.1 × 10 −7 M/s) are attributed to ultrafast electron transfer between Ag + and TMB, mediated by Ag 2 O intermediates formed from self-released alkaline ions. Additionally, self-released H 2 SiO 4 2− improves the stability of the oxidized substrate, resulting in a long-term stable colorimetric signal (∼20 min), which exhibits reliable accuracy regardless of the time point at which analyte is added within 20 min, thus eliminating the interference of individual operation time errors. Ascorbic acid (AA) is selected as the target molecule to assess the performance of the Ag 6 Si 2 O 7 -TMB colorimetric sensing system. This approach demonstrates a wide detection range from 5 to 300 μM and a detection limit of 0.452 μM. The developed colorimetric sensing strategy exhibits good stability, specificity, rapidity, and potential application in real sample detection.
研究领域:
生物化学
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分析化学
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医学诊断
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
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2016
·Vol. 45
·期 32
·12745-12755
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IF 4.177
Jun Liu,Wei Wu,Qingyong Tian,Zhigao Dai,Zhaohui Wu,Xiangheng Xiao,Changzhong Jiang
Coupling two different semiconductors to form composite photocatalysts is the most significant method for environmental remediation. In this regard, tube-like α-Fe2O3/Ag6Si2O7 heterostructures are synthesized via anchoring p-type Ag6Si2O7 nanoparticles (NPs) on the surface of n-type α-Fe2O3 short nanotubes (SNTs) by conventional wet-chemical routes. α-Fe2O3 SNTs are firstly fabricated by a hydrothermal method with the assistance of dihydrogen phosphate and sulphate. Then, Ag6Si2O7 NPs are anchored on α-Fe2O3 SNTs by an in situ deposition method, and the α-Fe2O3/Ag6Si2O7 p–n heterostructures are finally obtained. The morphologies, crystal structure, photocatalytic performance and photocurrent properties of as-synthesized α-Fe2O3/Ag6Si2O7 heterostructures are investigated. Six organic dyes are used for determining the high-efficiency Z-scheme photocatalytic activities of the as-obtained photocatalysts under ultraviolet and visible light (mercury lamp, 300 W). Compared with pure α-Fe2O3 SNTs, the photocurrent intensity of the α-Fe2O3/Ag6Si2O7 heterostructures is improved 62 times. The enhanced significant photocatalytic performance of α-Fe2O3/Ag6Si2O7 heterostructures could be attributed to charge transfer between Ag6Si2O7 NPs and the charge separation between Ag6Si2O7 NPs and α-Fe2O3 SNTs. These composite heterostructures are proposed to be an example for the preparation of other composite silicate photocatalysts for practical application in environmental remediation issues.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2019
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IF 6.361
Kun-Le Jia,Zhong-Shuai Zhu,Jin Qu,Ya-Qiong Jing,Xiao-Jie Yu,Yasmine Abdelkrim,Shu-Meng Hao,Zhong-Zhen Yu
Efficient separation of photogenerated electron-hole pairs is always one of the key factors boosting visible light photodegradation efficiency. Till now, there are few reports on the synergistic competitive consumption of photogenerated active species and the synergistic adsorption of organic contaminants to promote the performance of a designed heterojunction . Herein, we design and construct a novel BiOBr/Ag 6 Si 2 O 7 heterojunction with the dual synergistic effects towards methylene blue (MB) and methyl orange (MO). The dual synergistic effects could avoid the combination of photogenerated h + /e − pairs, improve the adsorption efficiency, and even regulate the photodegradation efficiency. Thus, for an aqueous mixture of MB and MO, the BiOBr/Ag 6 Si 2 O 7 photocatalyst exhibits largely improved adsorption capacities of the dyes by a multi-layer adsorption mode. Moreover, the photocatalyst could further promote the photodegradation rate of MO while slow that of MB due to the competitive consumption of photogenerated active species, showing a sequential selectivity phenomenon. Thanks to the dual synergistic effects, the adsorption capacity of MO increases 1379% higher than that of neat MO solution, and the photodegradation time decrease from 30 to 12 min with a rate constant of 0.22 min −1 , 38% higher than that of neat MO solution.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 47
·22550-22560
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IF 3.925
Lili Wang,Lei Chen,Mengyao Tang,Shoujie Jiang,Dawei Gao
A novel AgI/Ag6Si2O7/PET Z-scheme heterojunction photocatalyst with strong redox capability was fabricated via a facile successive ionic layer adsorption and reaction (SILAR) method to degrade methyl orange (MO). Compared with Ag6Si2O7/PET and AgI/PET, the prepared AgI/Ag6Si2O7/PET heterojunction exhibits superior photocatalytic performance under visible light because of its strong interfacial coupling effects. The degradation rate constant of the optimal AgI/Ag6Si2O7/PET is up to 0.144 min−1, which is approximately 5.5 and 9.6 times greater than that of Ag6Si2O7/PET and AgI/PET, respectively. The radical capture experiments and ESR characterization demonstrate that h+ and ˙O2− are two major oxidative species responsible for the photocatalytic degradation of dyes. The PL, photocurrent and EIS analyses indicate that AgI/Ag6Si2O7/PET shows enhanced electron–hole pair separation efficiency. This phenomenon is related to three aspects, namely the high light-harvesting efficiency, greatly enhanced accessibility to the active site, and the formation of Z-scheme heterojunction structures that effectively improve the photoelectron–hole separation efficiency and the redox capacity of the photocatalyst. Our work, therefore, provides novel insights into the development of a heterojunction composite with boosted photocatalytic activity, excellent stability, and reusability for the degradation of organic pollutants.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
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2025
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IF 5.4
Xiaohua Zheng,Zhongchen Chen,Chenbin Cai,Huilin Han,Ruomeng Zhang,Jingting Yang
In recent years, ternary heterojunction catalysts have emerged owing to their exceptional properties for integrating the advantages of various materials, enabling the efficient separation of photoinduced charges and enhanced redox performance. In this study, a novel dual Z -scheme g-C 3 N 4 /Ag 6 Si 2 O 7 /AgBr (CNASAB) photocatalyst was prepared using a one-step coprecipitation method. Its catalytic performance was assessed through the photodegradation of tetracycline hydrochloride (TC) and Rhodamine B (RhB). The results showed that among various CNASAB compositions, CNASAB6 exhibited the highest catalytic activity. The catalyst achieved complete degradation of RhB within 6 min under visible light irradiation, with catalytic rates 73.7, 53.0, and 6.8 times higher than those of the individual components, g-C 3 N 4 , Ag 6 Si 2 O 7 , and AgBr, respectively. Additionally, the catalyst exhibited significant degradation of TC with an efficiency of 63.38 % within 2 min, indicating a broadened degradation ability. Ultraviolet-visible diffuse reflectance spectroscopy, photoluminescence spectroscopy and electrochemical impedance spectroscopy analyses confirmed that the ternary heterojunction broadened the spectral response range, reduced electrochemical impedance, and improved the separation of photoinduced electron-hole pairs. The successful construction of this ternary heterojunction not only provides a promising strategy for the photocatalytic degradation of organic pollutants but also has substantial potential for environmental purification applications.
研究领域:
材料科学
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环境科学
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光催化
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纳米技术
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化学工程
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Tongtong Wang,Florian J. Stadler,Dalal Z. Husein,Di Zhang,Jinjun Cai,Yifan Wang,Minghao Li,Yin Qiang,Jiyong Zheng
To efficiently remove organic pollutants from wastewater combined with a disinfection effect, using activated biochar (ACB) as substrate, ACB-Ag 3 PO 4 and ACB-Ag 6 Si 2 O 7 composite photocatalysts were prepared via the in-situ co-precipitation method. The structure, morphology, physicochemical, and optical properties were characterized by advanced techniques, and the adsorption-photodegradation effects on tetracycline (TC), chloramphenicol (CAP), and rhodamine B (RhB) were investigated. The results revealed that ACB-Ag 3 PO 4 and ACB-Ag 6 Si 2 O 7 with heterojunction were successfully synthesized, and their optimum loading ratios were 1:1 and 1:2, respectively. The removal rates of ACB-Ag 3 PO 4 and ACB-Ag 6 Si 2 O 7 for TC were 98.48% and 91.87%, 95.88% and 85.23% for CAP, 99.13% and 83.54% for RhB, respectively, and also much higher than those of pure Ag 3 PO 4 and Ag 6 Si 2 O 7 . Moreover, the degradation efficiency and mineralization rate of ACB-Ag 3 PO 4 were higher than those of ACB-Ag 6 Si 2 O 7 for all pollutants. Further, both composites maintained about a 99% sterilization rate against both S. aureus and E. coli at 48 h. These were attributed to the introduction of ACB, which enriched the elemental composition of Ag-based semiconductors and increased the specific surface area and visible light absorption. Importantly, the composites narrow the bandgap energy and optimize energy band structure, and the special structure of ACB facilitated the photocatalytic activity . Moreover, possible photogenerated carrier transfer paths of the two composites are either type-II or Z-scheme, and the performance differences are related to the photogenerated carriers, absorbance, and microstructure. ACB-Ag 3 PO 4 is more recommended for environmental applications given its better photostability and reusability than ACB-Ag 6 Si 2 O 7 , and its removal of TC and RhB from actual wastewater exceeded 61.39% and 86.62%, respectively.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
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