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1.
Xiaoli Su Aihui Wang Linyuan Xu Wei Zhang Fumin Guo Dafeng Zhang Xipeng Pu Peiqing Cai 《Journal of the American Ceramic Society》2023,106(6):3594-3604
In this study, Ag2CO3/SnFe2O4 (Ag2CO3/SFO) photocatalyst was prepared by a simple hydrothermal-ultrasonic method for the efficient degradation of ciprofloxacin and phenol. The SFO nanoparticles were attached on the surface of Ag2CO3 rods synthesized by a low-temperature precipitation method, resulting a unique 1D/0D morphology, which increased the number of active sites. Due to introduction of magnetic SFO, Ag2CO3/SFO exhibited excellent magnetic recovery performance. When the mass fraction of SFO was 5%, the degradation efficiency of composite photocatalyst was the highest, the degradation rate for ciprofloxacin was 6.5 and 1.5 times higher than pure SFO and Ag2CO3, respectively. The improved photoactivity of Ag2CO3/SFO should be attributed to the construction of heterojunction with tight interface, which boosts the separation and transfer of photoinduced electron and hole pairs. On the basis of experimental results, a possible Z-scheme photocatalytic mechanism was discussed. Additionally, the excellent photostability of Ag2CO3/SFO was proved by a cycle experiment. 相似文献
2.
《Ceramics International》2020,46(9):13651-13659
Metal oxide photocatalysts have the disadvantages of large band gap and high internal resistance, and their photoelectrochemical properties are restricted. Metal selenides are generally characterized by narrow bandgap width, low internal resistance, high utilization rate of sunlight and superior photoelectrochemical performance. The ZnSe/MoSe2 heterostructure composite was successfully constructed by loading ZnSe nanoparticles onto MoSe2 nanoplates with three-dimensional flower-like structure. In this heterostructure composite, ZnSe nanoparticles are uniformly encapsulated by MoSe2 nanoplates, and the larger contact surface facilitates the transfer of carriers between heterojunction, while the three-dimensional flower structure of MoSe2 can transport and collect photogenerated carriers. This heterojunction composite has a full-band absorption capability of UV and visible light. Photocatalytic tests showed that the photocatalytic activity of the heterojunction photocatalyst was more than twice of MoSe2 and more than 4 times of ZnSe at the optimum ZnSe composite ratio, and photoelectric performance of that was 2.75 times of MoSe2. The results show that the photoelectrochemical performance of ZnSe/MoSe2 has been greatly improved, mainly because of the 0D/2D structure and band matching of ZnSe/MoSe2, so that the photogenerated electrons excited on the ZnSe conduction band can be transported to the conduction band of MoSe2, thereby improving the carriers’ separation efficiency and photoelectrochemical performance. 相似文献
3.
《Ceramics International》2015,41(7):8956-8963
The Ag3PO4/CeO2 heterojunction photocatalyst prepared by an ultrasound-assisted method exhibits an enhanced photocatalytic activity compared to pure Ag3PO4, CeO2, and Ag3PO4/CeO2 obtained without ultrasound action. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet–visible absorption spectroscopy (UV–vis), and the effects of ultrasound on the physicochemical properties and photocatalytic activity of Ag3PO4/CeO2 are discussed. Results show that the ultrasound-assisted synthesis method significantly improves the photocatalytic ability. The mechanism about the improvement was discussed in details. 相似文献
4.
《Ceramics International》2020,46(1):106-113
To develop a novel photocatalyst with high catalytic performance under sunlight, AgSCN/Ag3PO4/C3N4 heterojunction photocatalyst with Z-mechanism has been prepared, which demonstrates excellent photocatalytic performance for ibuprofen degradation. The catalytic activity of AgSCN/Ag3PO4/C3N4 is 1.5 and 3.3 times that of AgSCN/Ag3PO4 and Ag3PO4, respectively. The cyclic degradation number of AgSCN/Ag3PO4/C3N4 increases to seven because of the protection of AgSCN and C3N4 to Ag3PO4. The excellent photocatalytic performance of the AgSCN/Ag3PO4/C3N4 is attributed from the Z-mechanism with efficient separation efficiency of electron hole pair. 相似文献
5.
Liang Hao Yifei Hu Yan Zhang Xuecheng Ping Tongyang Liu Qian Zhao Yun Lu Jizi Liu 《Ceramics International》2021,47(6):7845-7852
A flexible TiO2 nanograss array film on Ti wire mesh was prepared by a mild chemical reaction. To overcome its shortcoming of almost no absorption of visible light, successive ionic layer adsorption and reaction (SILAR) was executed to decorate the prepared TiO2 film with BiOI. The results of XRD and SEM measurements showed that BiOI nanoflakes formed on the surface of TiO2 film, and the loading amounts of BiOI nanoflakes increased with the increase in SILAR cycles. The XPS results confirmed the heterojunction formation of BiOI-TiO2. The photocurrent measurement suggests that a moderate loading amount of BiOI nanoflakes is beneficial to improve the charge separation efficiency, which is ascribed to the heterojunction formation of BiOI-TiO2. The BiOI-decorated TiO2 film with SILAR cycles of seven showed the most excellent visible-light photocatalytic activity among all the samples. Compared with the bareTiO2 nanograss array film, its visible-light photocatalytic activity increased by 11.7 times. The flexible BiOI-decorated TiO2 nanograss array film with high photocatalytic activity shows great applications in air pollution and the pollution caused by offshore oil spills. 相似文献
6.
《Ceramics International》2023,49(7):10513-10524
Fabric-based nano semiconductor photocatalysts have attracted much attention in recent years. In this study, polyester fibers were modified by Ag2O/ZnO nanorod (NR)/Al-ZnO p-type/high resistivity/n-type (P-HR-N) heterojunction arrays. Al-doped ZnO (Al-ZnO) seed layer was reactively sputtered on polyester fibers. Al doping was used to change the work function (WF) of the ZnO film. The ZnO NR arrays were hydrothermally grown on the Al-ZnO seed layer and modified with Ag2O film. The work functions (WFs) of Ag2O and Al-ZnO layers were measured, resulting in and , respectively. The WF difference between the two layers was . The electron-hole separation of the P-HR-N heterojunction array was characterized by surface photovoltage (SPV) spectra. The photocatalytic activities of the prepared samples were investigated by removing Rhodamine B (RB) under UV irradiation. The P-HR-N heterojunction sample displayed a better photocatalytic performance than the Ag2O/Al-doped ZnO PN heterojunction sample and ZnO NR/Al-ZnO array-coated sample. The enhanced photocatalytic performance of the P-HR-N heterojunction based sample was mainly attributed to the high and widened built-in electric field (BEF) in the multilayer film. 相似文献
7.
《Ceramics International》2017,43(15):11588-11595
Ag3PO4/TiO2 nanosheet (TNS) heterojunction photocatalysts with almost 100% exposed (001) facets were fabricated via a facile in situ growth process. The Ag3PO4/TNS exhibited remarkable photocatalytic activity for the degradation of rhodamine B (RhB) and it was significantly more recyclable under sunlight compared with Ag3PO4. The RhB degradation efficiency was 99.11% after 50 min of sunlight irradiation, and was 85.8% after three cycles. The photocatalytic degradation mechanism of RhB over the Ag3PO4/TNS heterojunctions is driven by both photogenerated holes (h+) and ·O2− radicals. This efficient and reusable Ag3PO4/TNS heterojunction photocatalyst is not only suitable for fundamental research but also has potential for practical applications in the energy and environmental fields. This study demonstrates that applying morphology engineering to heterojunctions is useful for developing composite photocatalysts with greatly improved properties. 相似文献
8.
《Ceramics International》2016,42(12):13411-13420
The quest for cost-effective environmental remediation has motivated the research for highly efficient and stable photocatalysts capable of degrading pollutants under visible-light illumination. Ag-based visible-light-responsive photocatalysts demonstrate alluring properties and applications in the elimination of organic pollutants in wastewater, however they often suffer from inherent photo-corrosion under illumination. Herein, we report the facile solution-phase synthesis of silver carbonate (Ag2CO3) microcrystals with varied morphological features in different solvents. The size and morphology of Ag2CO3 materials can be tuned on the basis of varying types and ratios of solvents. The specific synthetic method allows the orientation controllable growth of Ag2CO3 microcrystals with variable length-to-diameter ratios, with the surface harvesting more solar energy, and the photocatalyst suppressing the electron-hole recombination. The enhancement in both the photocatalytic activity and photostability of Ag2CO3 catalysts is evident when AgNO3 and NaHCO3 are employed as stabilizers. Operating in the presence of 0.02 M stabilizer, the photocatalyst demonstrates highly efficient and robust degradation performance of higher than 95% in 5 successive times towards typical organic dye rhodamine B (RhB). Active holes and reactive oxygen-containing superhydroxyl radicals (·O2−) are determined by trapping experiments to be the main species responsible for improved photocatalytic performance. This work provides new insights into the development of high-performance, recyclable Ag-based photocatalytic materials for energy and environmental applications. 相似文献
9.
《Ceramics International》2022,48(11):15439-15450
A ternary photocatalyst of LaOCl/CeO2-g-C3N4 was designed and firstly synthesized by a facile KCl–LiCl molten salt method. The 60 %LaOCl/40 %CeO2-g-C3N4 with a 6: 4 weight ratio of LaOCl to CeO2 has an optimal degradation ratio (nearly 100%) for methylene blue (MB) with an impressive cyclic stability. Both of adsorption and photodegradation contribute to the high MB removal ratio, and kinetic study results show that the rate constant of photocatalytic degradation route is 0.0174 min?1, which is less than that of adsorption process (2.4406 min?1). The excellent adsorption performance of 60 %LaOCl/40 %CeO2-g-C3N4 is attributed to its negative zeta potential (?35.40 mV) and larger average pore size. The photochemical characterizations suggest that the 60 %LaOCl/40 %CeO2-g-C3N4 form a dual Z-scheme heterojunction, which enhances its separation efficiency of photogenerated e-/h+ with an outstanding redox ability, and further promotes the photocatalytic activity. 相似文献
10.
《Ceramics International》2023,49(3):4846-4854
In this research, a mesoporous rod-shaped ZnO/CuO/CeO2 n-p-n heterojunction has been designed via a two-step co-precipitation technique for photocatalytic applications. Characterization by powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), UV–Vis, and Scanning Electron Microscopy (SEM) techniques confirmed the formation of mesoporous rod-shaped ZnO/CuO/CeO2 n-p-n heterojunction having preferred interface developing between the ZnO, CuO, and CeO2 phases, thus extended the light-absorption window up to 800 nm. Under sunlight, the ability of a mesoporous ZnO/CuO/CeO2 n-p-n heterojunction to act as a photocatalyst was tested with methyl orange (MO) and crystal violet (CV) as target molecules. We found the degradation efficiencies of CV and MO dyes on mesoporous ZnO/CuO/CeO2 to be 96% and 88%, respectively, after 90 min of sunlight irradiation. The estimated rate constants (k, min?1) for deterioration of CV and MO under sunlight over ZnO/CuO/CeO2 composite were 0.039 and 0.022 min?1, respectively. We endorsed the greater photo-response, the well-aligned band-structure, and practical usage of the photo-induced carriers of the mesoporous photocatalyst to be the leading causes for the outstanding photocatalytic properties of ZnO/CuO/CeO2 n-p-n heterojunction. The ultimate oxidizing species that destroyed dyes were O2 ̄ and ·OH over ZnO/CuO/CeO2 photocatalyst under sunlight illumination. Besides, the recycling tests confirmed the high photostability of the ZnO/CuO/CeO2 photocatalyst. Hopefully, the mesoporous rod-shaped architecture of the n-p-n heterojunction with anticipated interface manufacturing will assist the photocatalyst strategy with better photocatalytic action under sunlight irradiation. 相似文献
11.
《Ceramics International》2018,44(18):22748-22759
The photocatalytic reduction method was used to introduce Ag nanoparticles (Ag NPs) into the Cu2O-TiO2 nanotubes (Cu2O-TNT) prepared by electrodeposition. The Z-scheme heterojunction Cu2O-Ag-TNT (CAT-4–60) catalysts were prepared. The mechanism of the transition from the traditional P-N heterojunction enhanced by noble metal to the Z-scheme heterojunction was studied. In addition, the Z-scheme heterojunction CAT-4–60 showed the highest light absorption and the highest photoelectrochemical activity under visible light, and the photoluminescence intensity was significantly reduced. Compared with the traditional P-N heterojunction CAT-2–60, not only the photocatalytic activity of the dual Z-scheme CAT-4–60 catalyst was improved, and the removal rate of MB was 98.58% higher than TNT (45.81%), CT-60 (69.49%), AT-2 (75.1%) and CAT-2–60 (91.2%),but also the stability of Cu2O in CAT-4–60 was significantly enhanced. This work reveals the potential application of noble metal nanoparticles to enhance the Z-scheme heterojunction under visible light-driven photocatalysis, and provides new insights to the transition from traditional P-N heterojunctions to Z-scheme heterojunctions. 相似文献
12.
《Ceramics International》2022,48(20):29722-29729
Two-dimensional (2D) transition metal chalcogenides (TMDs) have shown tremendous feasibility as building blocks for the development of high-performance optoelectronic devices owing to their distinct electrical and optical properties. However, the relatively narrow sensing range as well as the complex fabrication technique impede their technological applications. Here, we demonstrate the mixed-dimensional van der Waals (vdW) WSe2/Si 2D-3D vertical heterojunction by in-situ fabrication of WSe2 multilayer on pre-patterned Si, for broadband and fast-speed photodetection. Thanks to the novel high-quality vertical p-n heterojunction, the as-fabricated WSe2/Si photodetector shows an excellent rectifying characteristic and a prominent photovoltaic effect, making the device capable of light detection in self-driven mode. Additionally, the device reveals remarkable performance in terms of a high specific detectivity of ~8.79 × 1013 Jones, a large responsivity of ~294 mA/W, and a fast response time of 4.1 μs. Significantly, the device shows high sensitivity to a wide spectra (200–1550 nm) owing to the production of a type-II band structure of the WSe2/Si vertical heterojunction. The mechanism of photo-generated carriers separation and transfer in the heterojunction is analyzed by KPFM. Our work offers a potential route to the development of unique 2D-3D heterojunction for optoelectronic devices and system applications. 相似文献
13.
A novel photocatalyst AgAlO2/TiO2 with a p–n heterojunction structure was synthesized through the method that combined sol–gel and ion exchange. The as-synthesized samples were characterized by XRD, SEM and UV–vis. The photocatalytic activity of as-synthesized sample was evaluated and the possible mechanism was discussed. As-synthesized AgAlO2/TiO2 (in mass ratio of 90/10) exhibited remarkably high photocatalytic activity of 97.8% in decomposing formaldehyde under sunlight irradiation for 90 min. Our work provided a basic experimental process for AgAlO2/TiO2 heterojunction and explored the connection between p–n heterojunction and photocatalysis, which will possess a broad prospect in terms of the applications in improving indoor air quality. 相似文献
14.
《Ceramics International》2017,43(4):3706-3712
Silver phosphate is a promising photocatalyst since its energy band gap is situated in the visible range (Eg≈2.4 eV), thus this material is a potential candidate for replacing titania which is photoactive only under UV. However, Ag3PO4 suffers of photocorrosion and therefore composites should be prepared to limit this detrimental effect. In this work, pure Ag3PO4 and its composites with AgI, TiO2, and hydroxyapatite were prepared by using various methods. The photoactivity of the materials was evaluated by their ability to decolorize methylene blue and to mineralize phenol under non-filtered and UV-filtered artificial solar-like radiation. The use of UV cut-off filter enhanced the photocatalytic activity of pure silver phosphate by limiting the photocorrosion of silver(I) into Ag°. For composites with AgI and TiO2, despite their lower photoactivity compared to pure Ag3PO4, the efficiency in mineralization of phenol after repeated run is stabilized by using UV cut-off filter. On the other hand, the photocatalytic efficiency of Ag3PO4 composites containing hydroxyapatite remained low mainly due to high absorption properties of hydroxyapatite. The photoactive samples showed excellent photoinduced antimicrobial properties where Gram-negative E. coli was more susceptible to photocatalytic deactivation than Gram-positive S. aureus (MRSA). 相似文献
15.
《Ceramics International》2015,41(8):9671-9679
The present work is focused on the preparation of hybrid ZnO/TiO2/Ag2O nanocomposite for enhanced photocatalytic activity. The resultant samples are characterized by using XRD, SEM, EDX, HR-TEM, UV-DRS, BET and XPS techniques. X-ray diffraction analysis indicates the co-existence of wurtzite, anatase and cubic phases in ZnO/TiO2/Ag2O nanocomposite. The band gap energy value of the photocatalyst is 3.39 eV, which has been evidenced from UV–visible diffuse reflectance spectroscopy measurements. Photocatalytic degradation of methylene blue dye has been investigated by using UV–visible spectrophotometer. From the result, it has been concluded that ZnO/TiO2/Ag2O nanocomposite has proven to be an efficient photocatalyst under UV irradiation when compared to that of mono and binary oxide systems. Further, the possible photodegradation mechanism is proposed to support the enhancement of photocatalytic activity towards degradation of dyes. 相似文献
16.
《Ceramics International》2023,49(8):12327-12333
Keeping in view of the hazardous application of tetracycline hydrochloride antibiotic, an efficient CoFe2O4/NiFe2O4 heterojunction photocatalyst has been prepared hydrothermally by combining CoFe2O4 and NiFe2O4 nanoplates. The CoFe2O4/NiFe2O4 composite with the improved photocatalytic activity can be employed for removal of tetracycline hydrochloride antibiotic, comparing to the bare CoFe2O4 and NiFe2O4. The optimized sample 5%-CoFe2O4/NiFe2O4 shows the high photocatalytic degrading tetracycline with 76.1% removal efficiency in 60 min. These improved photocatalytic activities are attributed to the extended visible light absorption and enhanced charge separation following S-scheme route as confirmed from photoluminescence and electrochemical studies. From the charge trapping experiments, it is confirmed that superoxide radical and holes in the valence band of NiFe2O4 with high thermodynamic energies are responsible for the photodegradation of the target pollutant. This work provides sufficient attention towards the preparation of low cost materials for the removal of highly hazardous pollutants being present in water. 相似文献
17.
《Ceramics International》2019,45(12):15036-15047
A three-dimensional (3D) flower-like β-Bi2O3/Bi2O2CO3 heterojunction photocatalyst was synthesized via decomposition of the precursor fabricated using a composite soft template, which was constructed from dl-aspartic acid and nonionic amphiphilic triblock copolymer (Pluronic F127). The morphology, phase structure, composition, effect of reactant concentration, and possible formation mechanism were systematically studied. The results showed that dl-aspartic acid was chosen as the coordination- and structure-directing agent, while F127 was used as the capping agent during preparation of the precursor. The as-prepared flower-like β-Bi2O3/Bi2O2CO3 heterojunction obtained after calcination of the self-sacrificing precursor at 290 °C showed excellent photocatalytic performance in the degradation of the refractory colorless antibiotic agent tetracycline (TC) under simulated sunlight irradiation, with 98.79% TC degradation being achieved within 60 min of irradiation. This excellent photocatalytic performance was attributed to the narrow band gap, heterojunction structure, and 3D hierarchical structure. The results further revealed that photogenerated holes (h+) and hydroxyl radicals (•OH) dominated the photocatalytic process. Furthermore, the β-Bi2O3/Bi2O2CO3 heterojunction catalyst was not photocorroded after six consecutive cycles, suggesting an excellent photostability. 相似文献
18.
In this work, a ternary composite photocatalyst of graphitic carbon nitride (g-C3N4), graphene oxide (GO), and Ag3PO4 was prepared through a simple precipitation route, in which Ag3PO4 nanoparticles covered or wrapped with GO sheets are supported on g-C3N4 sheets. The composite photocatalyst displays enhanced absorption in the visible region, and exhibited superior photocatalytic activity compared with single-component or binary composite photocatalysts in the photocatalytic decomposition of Rhodamine B. The enhancement of photocatalytic activity could be attributed to the synergistic effect among them. The ternary composite also exhibited enhanced stability, but further efforts should be made to make it more stable. 相似文献
19.
Here we report the facile synthesis of Ag/Ag2O heterostructures, which exhibit excellent solar full spectrum (UV, visible and near-infrared) photocatalytic activity and an enhanced photoelectrochemical (PEC) performance under irradiation of near-infrared light. The improved photocatalytic property and PEC performance originated from the synergistic effect on the narrow band gap of Ag2O, plasmon enhancement of metallic Ag in-situ reduced from Ag2O, and metal-semiconductor (Ag-Ag2O) Mott-Schottky heterojunction. 相似文献
20.
Jinxiu Wang Xue Yang Jing Chen Jiangjun Xian Sugang Meng Yi Zheng Yu Shao Danzhen Li 《Journal of the American Ceramic Society》2014,97(1):267-274
In this study, pure Ag4V2O7 was synthesized via hydrothermal method without surfactant at different temperatures (100°C, 120°C, and 140°C) and pH values (4 and 5) for the first time. Moreover, Ag4V2O7 nanoparticles with homogeneous size distribution about 200–300 nm can be obtained by adding polyvinylpyrrolidone to the synthesis system. Effects of hydrothermal synthesis conditions on photophysical properties and photocatalytic activity of Ag4V2O7 were investigated systematically. Ag4V2O7 sample prepared at 120°C and pH = 4 had the optimal photocatalytic activity among these samples, which almost completely degraded 10 ppm Rhodamine B within 3 h under visible light irradiation (420 nm < λ < 800 nm). The degradation products were measured by liquid chromatography–mass spectroscopy. The active species involved in the degradation process were analyzed by means of adding active species scavengers, electron spin resonance techniques, and photoelectrochemical experiments. A possible mechanism for photocatalytic degradation of organic pollutants on Ag4V2O7 photocatalyst was proposed and discussed preliminarily. 相似文献