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In this study, Ag-AgCl/attapulgite (Ag-AgCl/ATP) composites were synthesized via a direct precipitation method using ATP nanorods as a catalyst supporter. ATP nanorods helped to increase the dispersion of Ag-AgCl particles and broaden the light absorption spectrum, which would also help to increase the active site of the catalyst to promote the degradation of tetracycline (TC). The photocatalytic activity of the Ag-AgCl/ATP composites was evaluated through the degradation of TC, identifying the loading amount of Ag-AgCl, the concentration of TC, and the reaction temperature as critical factors influencing activity. Specifically, the optimal conditions were observed when the loading of Ag-AgCl was 75%, resulting in a photocatalytic degradation efficiency of 77.65%. Furthermore, the highest degradation efficiency (85.01%) was achieved with a TC concentration of 20 mg/L at 20 °C. Radical trapping experiments suggested that the superoxide anion radical (·O2−) was the primary active species in the degradation process, although hydroxyl radicals (·OH) and holes (h+) also contributed. Reusability tests confirmed that the Ag-AgCl/ATP composites exhibited excellent stability and could be effectively reused. [ABSTRACT FROM AUTHOR]

The Ce doping TiO2/halloysite nanotubes photocatalyst (Ce-TiO2/HNTs) was prepared for enhanced photocatalytic degradation of tetracycline (TC). The crystal structure, morphology and photoelectrochemical (PEC) properties have been researched by XRD, TEM, UV–vis DRS and other characterized technologies. The TEM results showed that the Ce-TiO2 nanoparticles were evenly dispersed on the surface of HNTs with about 5 nm pore structure. The UV–vis DRS results showed that the doping of Ce effectively broadened the photo-absorption capacity of the pure TiO2. The PEC results confirmed that the doping of Ce decreased the electrochemical impedance of the photogenerated carrier in the transfer process and greatly improved the photogenerated efficiency of the electron within the TiO2 NPs. The XPS analysis showed that Ce co-existed in the form of Ce3+ and Ce4+ oxidation states in the Ce-TiO2/HNTs. The photodegradation experiments showed that Ce-TiO2/HNTs exhibited the enhanced photocatalytic activity under the visible-light irradiation compared with the pure TiO2 NPs. [ABSTRACT FROM AUTHOR]

In this work, thermo-responsive PNIPAM@AgBr/CSs composite photocatalysts were successfully fabricated by grafting method. The thermo-responsive composite photocatalysts were further characterized by SEM, EDS, XRD, FT-IR, DRS and PL, the results demonstrated that the surface of CSs was successfully loaded with AgBr and further grafted with PNIPAM, and the grafted PNIPAM not only obtained the thermo-responsive performance, but also synergistically enhanced visible light photocatalytic activity toward degradation of tetracycline (TC) antibiotics. The influenced factors of photocatalytic degradation were also investigated, the results showed that the dosage of PNIPAM and the reacted temperature were obviously affected the degradation rate of TC. Lastly, the photocatalytic degradation mechanism of as-obtained thermo-sensitive photocatalyst was also discussed in detail. This work might offer a way to obtain the intelligently composite materials for switchable photocatalytic processes. [ABSTRACT FROM AUTHOR]

High selectivity and fast charge separation are two important factors for photocatalytic wastewater treatment. Herein, we prepared a molecular imprinted Ag/Ag 3 VO 4 /g-C 3 N 4 photocatalyst (MIP) that exhibited great specific recognition ability along with excellent photocatalytic activity. The ultrathin g-C 3 N 4 nanosheets with high surface are used to prepare. The Z-scheme Ag 3 VO 4 /g-C 3 N 4 heterostructure and the surface plasmon resonance of the photoreduced Ag0 together contributed to the improvement of the separation efficiency of photogenerated electrons and holes. In addition, MIP provides the specific recognition ability to preferentially adsorb the target pollutant. The selectivity of photocatalysis was evaluated by the degradation of oxytetracycline and tetracycline solutions. Photoluminescence and transient photocurrent measurements further prove the improved charge separation efficiency of MIP. A plausible photocatalytic reaction mechanism is proposed based on electron spin resonance measurement and the active species trapping experiments, where indicates that the main active species of this photocatalytic process are O 2 − and h+. This research provides an effective strategy for the simultaneous enhancement of selectivity and activity via molecular imprinting. [ABSTRACT FROM AUTHOR]

Graphical abstract Schematic illustration of the formation of CQDs/ZnO@HNTs in the whole synthetic process. Highlights • We have experimentally demonstrated the carbon incorporated ZnO via coupling CQDs. A notable transformation of burger-like CQD s /ZnO morphology was observed and the HNTs have been introduced to improve the dispersity of hybrid photocatalysts. • From efficiently modulation of band structure of CQD s -based materials, the as-prepared CQD s /ZnO@HNTs display a remarkable optical excitation in photogenerated reactive oxygen species (ROS). • This work provides an efficient and novel strategy for element incorporated with introduced inorganic quantum dots owing to the quantum size effect. • It also developed a new sight of CQD s participated phase tuning for semiconductors, offering a beneficial route for expanding the application of VLD photodegradation based on band-tuning semiconductors and other low-dimension materials. Abstract Environmentally friendly photodegradation of refractory pollutants utilizing semiconductor photocatalysis evolution exhibits satisfactory efficiency and low energy consumption, but some of its unbefitting band position largely limits practical applications. The controllable band structure tuning via coupling low-dimensional materials with enormous potential in semiconductor photocatalysis, notably attractive carbon quantum dots (CQDs) induced for a better utilization of low-energy photoexcitation of promising inherent optical properties and photocatalytic performance on organic pollutant degradation. Here, a CQDs modified ZnO hybrid materials was synthesized and the CQDs preluded carbon-incorporated burger-like ZnO nanoparticles clusters were presented thus demonstrated a specific doping-effect. The dispersity improved by loading halloysite nanotube (HNTs) for efficiently photocatalytic activity enhancement. Furthermore, the band structure, excitation and photocatalytic reactive oxygen species (ROS) generation were detected to reveal the photochemical properties and plausible mechanism of CQDs hybrid nanomaterials system. It is observed that the superoxide radical (O 2 −), and singlet oxygen(1O 2) are the principal ROS agents under UV–vis excitations. This work not only displays a CQDs modified system of expanding photo-response range to visible light but also throws a way for quantum elemental incorporated on the influence of band-tuning for semiconductor- dominated photocatalysts. [ABSTRACT FROM AUTHOR]

The interfacial regulation strategy between semiconductors can effectively promote the separation efficiency of photogenerated carriers and enhance photocatalytic activity under the synergistic effect. Herein, AgInS 2 QDs-MoS 2 /GO (AIS-MS/GO) composites were prepared by interfacial coupling of AgInS 2 QDs (AIS), hierarchical MoS 2 and ultrathin GO. Ultrathin GO successfully solved the agglomeration problem of AIS and hierarchical MoS 2. Moreover, the photogenerated carriers were effectively separated and transferred under the synergistic effect of the AIS-MS heterojunction and ultrathin GO, thus promoting tetracycline (TC) degradation and CO 2 reduction performance. The degradation rate of tetracycline (TC) reached 96.5 %, and the yields of CO and CH 4 in the CO 2 reduction products reached 52.6 and 28.5 μmol g–1, respectively, when using the optimized photocatalyst. In-situ FTIR analysis indicated that TC is gradually degraded by small molecules on the composite surface, and has excellent dissociation ability of water molecules during the CO 2 reduction process. This work provides a new vision for the rational design of heterojunction-based photocatalysts using the interfacial regulation strategy for enhancing interfacial charge separation and photocatalytic performance. [Display omitted] • AIS-MS/GO composites were prepared via the interfacial regulation strategy. • The photogenerated carriers were effectively separated and transferred under synergistic and interfacial effects. • The aggregation problem of AIS and hierarchical MoS 2 was effectively solved. • AIS-MS/GO composites achieve a 96.5 % TC degradation rate and 35.1 % selectivity for CH 4. [ABSTRACT FROM AUTHOR]