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The Ag 2 O/Ag 2 CO 3 /multi-walled carbon nanotube (MWNTs) composite photocatalysts were prepared by calcination of the obtained precipitate. The structures and morphology of as-prepared composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS). The Ag 2 O/Ag 2 CO 3 /MWNTs composite photocatalysts exhibit higher degradation rate of ciprofloxacin (CIP) than the pure Ag 2 CO 3 , Ag 2 O/Ag 2 CO 3 and Ag 2 CO 3 /MWNTs under visible light irradiation. The amount of loaded Ag 2 CO 3 onto MWNTs and calcined time for Ag 2 CO 3 /MWNTs were systematically investigated, and the optimal amount of loaded Ag 2 CO 3 and calcined time of Ag 2 CO 3 /MWNTs are 150 wt% and 10 min, respectively. The highest photocatalytic degradation rate of CIP could reach 76% under optimal conditions. The active species trapping experiments were also analyzed, the results show that the holes are main contributor for the degradation processes of CIP, furthermore the electrons, O 2 − and OH are also crucially influenced the photocatalytic degradation processes of CIP. The possible photocatalytic processes of CIP with Ag 2 O/Ag 2 CO 3 /MWNTs composite photocatalyst are also proposed. [ABSTRACT FROM AUTHOR]

Ag/Ag 3 PO 4 /active carbon (AC) composite photocatalysts were successfully synthesized using the simple deposition and photoinduced methods. The structures, morphology and photocatalytic properties of as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS). The Ag/Ag 3 PO 4 /AC composite photocatalysts exhibited a conspicuously improved photocatalytic performance for tetracycline (TC) degradation. The optimal conditions of loaded dosage and photoinduced time were investigated, and the results showed that the photoinduced time played an important role in prepared processes, and also that for the loaded dosage of Ag 3 PO 4 . The DRS analysis showed that the composite photocatalysts exhibited strong absorption ability in the visible light range. The radicals trap experiments demonstrated that there were multiple active species during the degrading process of TC. The possible mechanism of improved photocatalytic activity of Ag–Ag 3 PO 4 /AC composite was also proposed. [ABSTRACT FROM AUTHOR]

The graphitic carbon nitride (g-C 3 N 4 ), as one photocatalyst which possess the suitable band gap, is better for modified TiO 2 and enhanced photocatalytic degradation of organic pollutants. In this work, the g-C 3 N 4 /TiO 2 were successfully prepared via directly calcined the mixture of melamine and P25. The as-prepared g-C 3 N 4 /TiO 2 photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and high resolution electron microscopy (HRTEM), Raman and Fourier transform-infrared spectroscopy (FT-IR). The photocatalytic performances of g-C 3 N 4 /TiO 2 composites were investigated by degradation of ciprofloxacin. The results showed that the g-C 3 N 4 and P25 were successfully composited, and the bond of C–N was well formed, the calcined temperature for as-prepared photocatalysts and the ratio of melamine and P25 were important to the degradation rate of ciprofloxacin. When the mixture of melamine and P25 with 1:2, and calcined temperature at 600 °C, the degradation rate of ciprofloxacin could reach 95% in 60 min. The enhanced photocatalytic performances could be mainly attributed to the suitable band gap structure with heterojunction of CN-P25. Finally, the possible transferred processes of photoelectrons and photoholes were proposed. [ABSTRACT FROM AUTHOR]

• The g-C 3 N 4 /7Ag/m-CeO 2 composite photocatalyst was successfully synthesized. • The introduction of g-C 3 N 4 nanosheets alleviated the photocorrosion of Ag. • The g-C 3 N 4 /7Ag/m-CeO 2 exhibits higher activity for CO 2 photoconversion. In this work, the ordered mesoporous CeO 2 (m-CeO 2) was successfully fabricated via the nanocasting pathway, through using SBA-15 as a hard template. Besides, g-C 3 N 4 /Ag/m-CeO 2 composite was successfully constructed by calcination method. Meanwhile, the obtained samples were investigated by series of test techniques. The XRD, SEM and TEM results show that the m-CeO 2 and Ag/m-CeO 2 with the ordered mesoporous trait. Besides, the EPR, Raman and XPS results suggest that the oxygen vacancies (O v) and Ce3+ and Ce4+ are in g-C 3 N 4 /Ag/m-CeO 2. In addition, the ordered mesostructure is favorable for the CO 2 molecular movement and adsorption/desorption reaction. The g-C 3 N 4 nanosheets, a promising material possessing suitable conductor band, large specific area, non-toxicity, and outstanding chemical stability, is a candidate semiconductor for CO 2 conversion. The introduction of g-C 3 N 4 nanosheets to Ag/m-CeO 2 overcomes the photocorrosion of Ag nanoparticles and Ag facilitate the transfer of photogenerated electrons. The photocatalytic activity results show that when the loading of Ag is 7 wt%, the g-C 3 N 4 /7Ag/m-CeO 2 composite exhibits the superiority activity for CO 2 photoconversion to CO (13.94 μmol/g) and CH 4 (7.39 μmol/g) under UV-irradiation in 10 h. [ABSTRACT FROM AUTHOR]

• MgZnO:F films with high Mg content were synthesized by RF magnetron co-sputtering. • Structural, electrical and optical properties of the films were investigated. • F occupied O sites, decreased the resistivity without reducing optical loss. • Low resistivity and high carrier concentration were simultaneously realized. Fluorine-doped Mg 0.21 Zn 0.79 O (MZO:F) thin films were successfully deposited on glass substrates at room temperature by radio frequency (RF) magnetron co-sputtering method with Mg 0.21 Zn 0.79 O, MgF 2 , and ZnF 2 targets. Low resistivity (1.26 × 10-1 Ω⋅cm), high Hall mobility (3.55 cm2/Vs) and high carrier concentration (1.39 × 1019 cm−3) were simultaneously realized in the annealed MZO:F film. The effects of doping concentration and annealing temperature on the structural, morphological, electronic, electrical and optical properties of MZO:F films were systematically investigated in this study. XRD and XPS analysis confirmed that F atoms have entered into crystal lattices of MZO and acted as donors when they occupied O sites in the hexagonal lattice. Moreover, it was observed that both doping concentration and annealing temperature greatly affected the crystallinity, grain size, growth orientation and surface morphology of the MZO:F thin films. In addition, the optical gap changed dramatically with the F content and annealing temperature, which could be attribute to the Burstein-Moss effect accompanied by the effects of fluctuating potential arising from the randomly situated impurities. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual-plasma enhanced g-C 3 N 4 /Pd/MoO 3-x heterojunction was fabricated for high-selectivity photocatalytic CO 2 reduction. • The g-C 3 N 4 /Pd/MoO 3-x composites revealed excellent near-infrared absorption ability. • The carrier separation efficiency was effectively improved under the synergistic effect of MoO 3-x and Pd nanosheets. • The g-C 3 N 4 /Pd/MoO 3-x S-scheme heterojunction displayed high photocatalytic performance and CO selectivity. • The S-scheme charge transfer mechanism was proposed based on UPS and ESR results. The localized surface plasmon resonance (LSPR) effect has shown significant progress in enhancing the efficiency of light absorption and separating photogenerated carriers. Herein, the dual-plasma enhanced 2D/2D/2D g-C 3 N 4 /Pd/MoO 3-x (CPM) S-scheme heterojunction photocatalysts were synthesized using the method of hydrothermal and electrostatic self-assembly for high-selectivity photocatalytic reduction of CO 2 to produce CO. The dual LSPR effect of MoO 3-x and ultrathin Pd nanosheets synergistically broadened the optical response range of the CPM composites and successfully improved the photocatalytic activity and near-infrared (NIR) performance. The optimized CPM-30 photocatalysts exhibited CO yields of 18.55 μmol g−1 with a selectivity of 96.3%. In addition, the CO yield reached 3.92 μmol g−1 after 4 h of NIR light photoirradiation. The electron spin resonance (ESR) and ultraviolet photoelectron spectroscopy (UPS) tests showed that the S-scheme heterojunctions were constructed by coupling g-C 3 N 4 /Pd nanosheets and MoO 3-x. This work will provide a reference for improving product selectivity through the design of two-dimensional composites and the utilization of plasma materials. [ABSTRACT FROM AUTHOR]

A multiple transmission channels, heterojunction and 3D PCN/AgBr/rGO photocatalyst was successfully synthetized by introducing the reduced graphene oxide (rGO) covering AgBr onto the surface of 3D porous g-C 3 N 4 (PCN). In PCN/AgBr/rGO, PCN as a semiconductor photocatalyst provides the 3D framework, the heterojunction was formed with AgBr particles and PCN, rGO promotes the electron transfer simultaneously and introduces a multiple transmission channels system to increase the active species. Thanks to the heterojunction formed between PCN and AgBr, resulting rapid separation of photo-generated e − /h + at interface. The 3D PCN/AgBr/rGO nanocomposite exhibits excellent photocatalytic efficiencies for tetracycline (TC) up to 78.4% within 90 min and 2,4-dichlorophenol (2,4-DCP) up to 68.2% within 6 h. The photocatalytic rate of PCN/AgBr/rGO was much higher than 3D PCN (21%), AgBr particles (31%) and most of g-C 3 N 4 -based photocatalysts in TC degradation. Moreover, the PCN/AgBr/rGO shows high photocatalytic stability due to the significantly photocatalytic stability after four photo-degradation cycles. This study highlights the potential application of PCN/AgBr/rGO highly efficient waste water purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • The UCN@ZIS/SWNTs composite with different V Zn concentrations was constructed for photocatalytic CO 2 reduction. • The UCN was acidified to regulate the surface-active site for CO 2 activation and H 2 O dissociation. • The SWNTs further improves the separation efficiency of photogenerated electron-hole pairs by providing charge transfer channels. • The UCN@rZIS/SWNTs composite displays excellent photocatalytic performance and CH 4 selectivity. Zinc vacancy (V Zn) concentrations were successfully regulated on the hierarchical flower spherical ZnIn 2 S 4 (ZIS) by controlling the hydrothermal temperature. The photo-electrochemical experiments indicated that the carrier separation efficiency of ultrathin-g-C 3 N 4 @ZIS/SWNTs (UCN@ZIS/SWNTs) composite with different V Zn concentrations (poor-V Zn ZIS (pZIS) and rich-V Zn ZIS (rZIS)) had an efficient improvement because of the construction of UCN@ZIS heterojunction and the multiple channels for charge transfer provided by SWNTs. In-situ FTIR results indicate that the presence of V Zn and the enriched surface-active site on UCN contributes to CO 2 activation and H 2 O dissociation. Additionally, the yield of CO and CH 4 over UCN@rZIS/SWNTs composite reached 33.7 µmol g−1 and 39.8 µmol g−1, respectively, and the selectivity of CH 4 reached 54.1 % under the synergistic effect of V Zn , the surface-active site of UCN and charge-transfer channels. This work established an ideal defect model for enhancing CO 2 photocatalytic reduction performance and product selectivity, which may provide a new way to improve photocatalytic efficiency and a better understanding of the photocatalytic reaction mechanisms. [ABSTRACT FROM AUTHOR]

S-scheme heterojunction of In 2 O 3 /H 1.5 CN/2Au was prepared by hydrothermal, acidizing and calcination methods. The two-dimensional thin layer H 1.5 CN avoided the aggregation of In 2 O 3 and completed the S-scheme charge transfer with In 2 O 3. Moreover, Au not only enhanced the visible light absorption capacity of composites but also provided more active sites for CO 2 reduction. [Display omitted] • S-scheme heterojunction of In 2 O 3 /H 1.5 CN/2Au achieve CO 2 photocatalytic conversion to CO and CH 4. • The enhanced photocatalytic activity results from effective interfacial charge migration and separation and increased active sites. • The LSPR effect of Au improves the utilization of visible light. The construction of S-scheme heterojunction is of great significance for the photocatalytic reduction of CO 2. Here, we prepared two-dimensional (2D) ultra-thin g-C 3 N 4 by acidifying the carbon nitride precursor, and used In 2 O 3 to construct a S-scheme heterojunction with 2D g-C 3 N 4 , and finally In 2 O 3 /H 1.5 CN was modified with Au nanoparticles. The physicochemical properties of the prepared materials were studied by SEM/TEM, XPS, DRS, PL and photochemical test. Meantime, the S-scheme charge transfer mechanism was demonstrated by UPS and ESR. As a result, on the one hand, S-scheme heterojunction accelerated the transfer of electrons on the CB of In 2 O 3 to the VB of g-C 3 N 4 , avoided the recombination of photon-generated carrier. On the other hand, Au, as an effective cocatalyst, promoted photoinduced electron transfer and provided more active sites for CO 2 reduction and the local surface plasmon resonance phenomenon caused by Au NPs enhanced the visible light absorption capacity of the composite material. Moreover, 2D thin layer of g-C 3 N 4 played a carrier effect to disperse In 2 O 3 cube. Therefore, In 2 O 3 /H 1.5 CN/2Au had stable CO 2 reduction products, and the yields of CO/CH 4 reached 141.24/77.05 μmol/g. [ABSTRACT FROM AUTHOR]

rGO modified g-C 3 N 4 /R-CeO 2 Multi-interface contact S-scheme heterojunction photocatalyst maximizes the transfer efficiency of photogenerated electron and the CO 2 adsorption ability, thus greatly improving the CO 2 photoreduction performance. [Display omitted] • 2D-1D-2D g-C 3 N 4 /R-CeO 2 /rGO photocatalyst has been prepared for CO 2 photoreduction. • 2D-1D-2D multi-interface contact structure is of help for carrier transfer process. • π-π conjugation effect and Ce4+/Ce3+ transformation facilitate electron transmission. • In-situ FTIR and 13C isotope tracer tests analysis the CO 2 photoreduction mechanism. Construction of multi-interface contact step-scheme (S-scheme) photocatalyst is a promising pathway to achieve high-electron transfer efficiency for photocatalytic CO 2 reduction. In this paper, g-C 3 N 4 nanosheets were selected as the main photocatalyst, rod-like CeO 2 (R-CeO 2) with unique Ce4+→Ce3+ conversion property and rGO were loaded on the g-C 3 N 4 surface to construct 2D-1D-2D sandwich photocatalyst. The yields of CO and CH 4 were about 63.18 and 32.67 μmol/g after 4 h when the rGO/R-CeO 2 /g-C 3 N 4 was used as catalyst, which were about 4 and 6 times higher than that of pure CN, respectively. Cyclic experiments proved that the composite had excellent photocatalytic and material stability. Photoelectrochemical tests showed that the construction of S-scheme electron transfer model and the introduction of rGO can great enhance the electron transmission and separation of photogenerated electron-hole pairs. CO 2 adsorption test identified that the loading of R-CeO 2 and rGO obviously enhanced the CO 2 adsorption ability of pure g-C 3 N 4. Density functional theory (DFT) calculations used to analyze the electron transfer path and the formation of the build-in electric field at the semiconductor interface. In-situ FTIR and 13CO 2 element-tracer detection carried out to research the process of CO 2 photoreduction. A possible multi-interface contact S-scheme electron transfer mechanism for enhanced CO 2 photoreduction activity has been discussed. [ABSTRACT FROM AUTHOR]

Pt@CeO 2 /3DCN heterojunction are prepared by calcination method and photoreduction technology. The enhanced photoreduction of CO 2 performance can be ascribed to the synergistic effects of the oxygen vacancies in CeO 2 for CO 2 activation and heterojunction for electron separation. Besides, Pt nanoparticles (NPs) on CeO 2 /3DCN can further promote the transfer of electrons, resulting in higher photocatalytic activity. • The Pt@CeO 2 /3DCN photocatalyst was successfully synthesized. • Pt@45CeO 2 /3DCN exhibit best ability of CO 2 photoreduction under UV light. • The synergy of CeO 2 and 3DCN improves the photocatalytic performance. The conversion of CO 2 into high value-added carbon-based compounds through photocatalytic reduction technology is considered as one of the more promising strategies to solve the greenhouse effect. And construction of heterojunction photocatalysts can promote the separation of photoelectron-hole pairs, so as to achieve higher activity of photocatalytic CO 2 reduction. Hence, Pt@CeO 2 /3DCN heterojunction are prepared by calcination method and photoreduction technology. The photocatalytic results revealed that Pt@CeO 2 /3DCN show better photocatalytic activity for reducing CO 2 into CO and CH 4 , compared with 3DCN. Especially, Pt@45CeO 2 /3DCN shows the maximum photocatalytic activity of 4.69 and 3.03 μmol·h−1·g−1 for CO and CH 4 under UV light irradiation, respectively, and the reduction activity did not decrease significantly after five cycles. The enhanced photoreduction of CO 2 performance can be ascribed to the synergistic effects of the oxygen vacancies in CeO 2 for CO 2 activation and heterojunction for electron separation. Besides, Pt nanoparticles (NPs) on CeO 2 /3DCN can further promote the transfer of electrons, resulting in higher photocatalytic activity. [ABSTRACT FROM AUTHOR]

Ni x Co 2 Al-LDHs@CC is generated on the carbon cloth by hydrothermal method. The morphology and electrochemical performance are changed by adjusting the molar ratio of Ni to get the best electrochemical performance of Ni 1 Co 2 Al-LDHs@CC. The Ni 1 Co 2 Al-LDHs@CC has a high specific capacity of 1772.5 mC cm−2 at a current density of 1 mA cm−2 and it maintains outstanding capacitive retention of 93.3% after 12,000 cycles. • The effect of Ni on morphology, specific surface area and electrochemical properties of NiCoAl-LDHs is studied for the first time. • Ni 1 Co 2 Al-LDHs@CC with ultrathin nanosheet (15 nm) is synthesized by hydrothermal method. • Ni 1 Co 2 Al-LDHs@CC achieves the maximum specific capacity of 1772.5 mC cm−2. • An asymmetric supercapacitor (0.102 mWh cm−2) can light an 8 mm LEDs. Layered double hydroxides (LDHs) is a promising electrode material for supercapacitors (SCs) because its large specific surface area and anionic tunability. Herein, an ultrathin ternary Ni x Co 2 Al layer double hydroxides nanosheet (Ni x Co 2 Al-LDHs) grown on carbon cloth (CC) substrate by hydrothermal synthesis method is reported as a high efficiency battery-type electrode in alkaline medium. The influence of Ni on the electrochemical properties and morphology of ternary metal hydroxide is first studied. By adjusting the molar concentration of nickel, we determine that Ni 1 Co 2 Al-LDHs@CC has the best electrochemical performance. The Ni 1 Co 2 Al-LDHs@CC has a high specific capacity of 1772.5 mC cm−2 at a current density of 1 mA cm−2 and it maintains outstanding capacitive retention of 93.3% after 12,000 cycles. In addition, the obtained Ni 1 Co 2 Al-LDHs@CC//AC asymmetric supercapacitors (ASC) achieves a maximum energy density of 0.102 mWh cm−2 at power density of 0.75 mW cm−2 and keep the capacitance retention of 90.98% after 12,000 cycles to successfully light LEDs (8 mm). Detailed electrochemical kinetic analysis showed that the total capacitance of Ni 1 Co 2 Al-LDHs@CC electrode come from its effective capacitive storage mechanism. It is founded that Ni has influence on the morphology and electrochemistry of ternary metal hydroxide, which provided an effective design idea and method for improving the capacitance of ternary metal hydroxide. [ABSTRACT FROM AUTHOR]