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In this study, a series of CuO/CdS composites were synthesized by thermal oxidation and successive ionic layer adsorption and reaction (SILAR). The as-prepared CuO/CdS composites were investigated by x-ray diffraction (XRD), field emission high-resolution scanning electron microscopy (FESEM) and energy-dispersive spectrometry. Their photocatalytic activity was investigated by monitoring the degradation of methylene blue (MB) under ultraviolet and visible light irradiation. The XRD pattern indicated that the precursor was cubic-phase CuO and Cu2O. FESEM results indicate that changes in annealing time and temperature have an effect on morphology, but the nanowire structures are preserved. The growth mechanism of the CuO nanowires is discussed in detail. Furthermore, the photocatalytic degradation rate of the MB, determined using an ultraviolet-visible spectrophotometer (UV-vis, UV-2600, Shimadzu), indicates that CdS can significantly improve the absorption of visible light from the sun.

In this work, we explore the synergy of the photocatalytic reaction endowed with improvement of self-cleaning performance. A ZnO/CdS heterostructure was successfully synthesized by hydrothermal-chemical bath deposition on a zinc substrate. The effect of different experimental parameters for its structure and properties were systematically studied using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and UV–Vis spectrophotometry. In addition, superhydrophobic ZnO/CdS was treated by stearic acid modification with a contact angle as high as 160 ± 1.5° and rolling angle as low as 5 ± 1.2°. In the self-cleaning test and photocatalytic degradation test, the superhydrophobic heterostructure exhibited excellent anti-fouling properties and photocatalytic performance. Moreover, after the photocatalytic degradation test, the contact angle of the modified superhydrophobic surface remained 142 ± 2.4°.

Nanomaterials have been widely used in the fields of photocatalysis, sensors, and solar cells due to their excellent properties. However, nanomaterials are mainly prepared under nonlimited conditions. With the development of biomimetic nanochannels, their gating properties and chemical stability have come to the fore. Inspired by the potential applications of biomimetic nanochannels, it is significant to synthesize nanomaterials inside biomimetic nanochannels under limited conditions for facilitating newer applications. Therefore, we used an anodic aluminum oxide (AAO) template with different pore diameters as the limited condition to synthesize CdS structures via different synthesis methods. We successfully synthesized CdS nanoparticles and flower-like CdS structures in AAO nanochannels by the electrochemical-assisted method or solution impregnation method. Field-emission scanning electron microscope (FESEM) results revealed that the CdS nanoparticles would agglomerate together to form irregular bulks with an increase in the applied voltage; flower-like CdS structures would block the AAO nanochannels for longer reaction times and higher concentrations. Energy-dispersive spectrometer (EDS) and X-ray diffraction (XRD) results revealed that these structures self-assembled into AAO nanochannels were, in fact, CdS. In conclusion, these methods can provide important guidelines for nanomaterial synthesis in AAO nanochannels.

The integration of photocatalytic materials and self-cleaning superhydrophobic materials provides a possibility of combining decontamination and antifouling. Herein, considering the ability of TiO2 in the photocatalytic degradation of pollutants, morphology-controllable TiO2 nanotube arrays (TNAs) were successfully synthesized by adjusting the anodizing and annealing parameters of anodic oxidation. On this basis, superhydrophobic states on 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PTES)-modified TNAs and stearic acid (SA)-modified TNAs were fabricated by means of a facile impregnation method. The TNAs prior to and after modification were characterized by powder X-ray diffraction (XRD) for determining the phase structure, field emission scanning electron microscopy (FESEM) for determining the surface morphology, energy dispersive spectroscopy (EDS) for determining the chemical composition, ultraviolet-visible spectroscopy (UV-Vis) for determining the light absorption performance and a droplet shape analyzer (DSA) for determining surface wettability. The photocatalytic degradation efficiency of methylene blue was investigated, and the synergistic effect of photocatalysis and self-cleaning was well-established from the photocatalytic tests and self-cleaning simulation tests. Compared with untreated TNAs, the modified superhydrophobic TNAs not only maintained better photocatalytic performance, but also possessed the ability to further remove the residual pollutants on the superhydrophobic surfaces by a self-cleaning effect; thus, they have profound impacts on and potential applications in both photocatalysis and self-cleaning.

Noble metal deposition is one of the most effective optimization methods for improving the photochemical properties of metal semiconductor oxides. In this paper, vertically aligned CuO nanowires were synthesized by means of a facile thermal oxidation method on Cu mesh. Subsequently, Ag nanoparticles were deposited on the surface of the CuO nanowires by vacuum coating, forming a CuO/Ag composite nanostructure. The morphology, phase structure, elemental distribution, wetting properties and optical properties of the CuO/Ag composite nanostructures were characterized by field emission scanning electron microscopy, x-ray diffraction, energy dispersion spectrometry, contact angle measurement and UV–Vis spectrophotometry, respectively. We also explored the effect of the amount of Ag nanoparticle deposition on the structure and properties of CuO/Ag composite nanomaterials. The CuO/Ag composite nanostructures exhibited better photocatalytic properties and were found to effectively degrade organic pollutants in sewage, after Ag nanoparticle deposition.

The composite of semiconductor photocatalytic materials can effectively improve the solar energy utilization efficiency and quantum efficiency. Therefore, composite semiconductor materials have gradually become one of the most promising photocatalyst for solving water pollution problems. In this work, CuO nanowire arrays were prepared on Cu substrate by a thermal oxidation method, then CuO/CdS composite nanostructure was synthesized through an SILAR technique sequentially. The morphology, micro-area element composition, phase structure and optical properties of CuO/CdS nanostructure were characterized by field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, ultraviolet–visible and photoluminescence spectroscopy respectively. Based on the test results, we systematically discussed the effects of several experimental conditions such as copper substrate, annealing temperature and reaction time on the properties and structure of CuO/CdS composite nanostructure. The resultant binary CuO/CdS composite nanostructure exhibited more excellent photocatalytic activity than pure CuO nanowire arrays both in the photodegradation of simulated contaminant methylene blue (MB) and practical pollutants of sewage.

In order to understand the nanostructure-based architectures and phase structures of CdS on the photocatalytic property, we have synthesized 3 D flower-like CdS with cubic phase and hexagonal phase CdS nanoparticles by hydrothermal method. The as-prepared samples have been characterized by XRD, FESEM, and UV–Vis. The photocatalytic activity has been evaluated by the photocatalytic degradation of methylene blue (MB) under simulated visible-light irradiation. FESEM results reveal that the morphologies of cubic phase CdS are flower-like structures, and the morphologies of hexagonal phase CdS are nanoparticles. The optical energy band gap of flower-like CdS is 2.25 eV from UV–Vis result. Moreover, the flower-like CdS exhibits better photocatalytic activity and its highest degradation rate to MB can reach 90.4% than that of CdS nanoparticles.

CdS has been widely used in photocatalysis, by virtue of its sensitivity to visible-light irradiation. But CdS has two crystalline phases, which are not equally well understood. Hence, we synthesized cubic phase and hexagonal phase hierarchical CdS with different Cd sources by the hydrothermal method. These as-prepared CdS samples were characterized by powder x-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), ultraviolet–visible spectrophotometer (UV–Vis), and room temperature photoluminescence (PL). Photocatalytic degradation of methylene blue was evaluated under simulated visible-light irradiation. PXRD results revealed that the CdS samples manifested a cubic phase when the Cd source was CdCl2, but the CdS assumed a mixed hexagonal and cubic phase when the Cd source was Cd(NO3)2. FESEM results indicate that the morphologies of CdS are both flower-like structures. The optical energy band gap of cubic phase CdS is 2.26 eV, but mixed hexagonal and cubic phase CdS is 2.24 eV according to UV–Vis results. PL results show that CdS samples of both phases have a similar emission peak near 560 nm, which is consistent with UV–Vis absorption spectrums. In addition, mixed hexagonal and cubic phase CdS exhibits better photocatalytic activity than cubic phase CdS.

CdS is a well-known visible-light-sensitive semiconductor and has been widely used in photocatalysis. In order to improve the photocatalytic activity of CdS, controllable synthesis with different morphologies has been focused on. In this work, CdS structures with different kinds of surfactants were synthesized by the hydrothermal method. The as-prepared samples were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), and fluorescence spectroscopy (PL). Their photocatalytic activities were evaluated by the photocatalytic degradation of methylene blue (MB) under simulated visible-light irradiation. The XRD and EDS results revealed that fishbone-like CdS exhibited the hexagonal phase. The FESEM results showed that the morphologies of CdS indicated microsphere structures, flower-like structures, and branch-like structures when we added hexadecyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyethylene glycol (PEG 2000), respectively, as surfactants. The possible growth mechanism of CdS with different surfactants was explained. The UV-Vis results showed that the band gap of fishbone-like CdS was 2.32 eV, while the band gaps of CdS were 2.22 eV, 2.30 eV, and 2.31 eV for CTAB, SDS, and PEG 2000, respectively, when the concentration was 0.005 g mL−1. The photocatalytic results showed that the highest degradation rates of MB were 90.0%, 87.9%, and 87.5% for the different kinds of surfactants, which were consistent with the UV-Vis and PL results. The CdS microspheres displayed photocatalytic stability to MB. The trapping experiments indicated that the photogenerated electrons played a key role in the photocatalytic degradation of MB. Briefly, different kinds of surfactants have obvious effects on the structure and photocatalytic performance of CdS.

In recent years, visible light-driven photocatalysts used for confronting energy shortages and environmental pollution have drawn much attention. CdS is regarded as an excellent photoelectric semiconductor for photocatalysis, but photocorrosion and low photocatalytic activity limit its practical application. In order to improve the photocatalytic performance of CdS, we synthesized a II-type CdS/CuS composite via a hydrothermal method in one step. CdS, CuS and the CdS/CuS composite have flower-like structures according to FESEM results. XRD and EDS results confirm that the composite is composed of CdS and CuS, indicating that we have successfully synthesized the CdS/CuS composite. UV-Vis and PL results show that the formation of heterojunction structures with CuS can be used to control the optical properties of CdS. H2 evolution results show that the CdS/CuS composite generates H2 at a rate of 295 μmol g−1 h−1, which is higher than that of CdS.

The union of chemical compositions substitution and spectral controlling is of importance for the discovery of new materials or the implementation of properties optimization. In this work, we employed an effective strategy to regulate crystal structures by chemical unit co-substitution. We applied this strategy to Eu3+-doped Sr2(Al1−xMgx)(Al1−xSi1+x)O7 (0 ≤ x ≤ 1) solid solution phosphor, which was successfully synthesized by high temperature solid state reaction. The crystal structure remained the same group, P-421m, with controlling chemical compositions. The excitation peaks shifted between 263 and 270 nm and emission peaks shifted between 612 and 614 nm with a decreasing Stocks shift in overall tendency. The shift trend was clarified by Crystal Field Theory. The energy band structure and density of states of Sr2Al2SiO7 and Sr2MgSi2O7 were calculated by Density Functional Theory using the generalized gradient approximation. The band gap was also analyzed by diffuse reflectance spectrum as a contrast. The morphology was characterized by field emission scanning electron microscopy. Furthermore, the photoluminescence color of phosphors could be tuned from yellow to orange.

Metal oxide semiconductor materials have a wide range of applications in the field of solar energy conversion. In this paper, CuO was prepared directly on copper foam substrate by anodic oxidation. The effects of current density and anodizing temperature on sample preparation and performance were studied. Field emission scanning electron microscopy (FESEM) and X-ray diffractometer (XRD) had been used to determine the morphology and phase structure of the sample, and its optical and electrical properties were discussed through UV-vis spectrophotometer and electrochemical tests. In addition, the influences of experimental conditions such as current density and reaction temperature on the morphology and properties of CuO were systematically discussed. The FESEM images showed that as the anodic oxidation temperature increase, the morphology of the prepared sample changed from nanowires to leaf-like CuO nanosheets. According to the results of XRD, the structure of prepared CuO was monoclinic, and the intensity of diffraction peaks gradually increased as anodizing temperature increased. We found that the optimum current density and anodizing temperature were 20 mA cm&minus, 2 and 60 &deg, C, respectively. The results of electrochemical indicated that the CuO electrode based on copper foam (CuO/Cu foam) prepared at the optimum exhibited the highest specific capacitance (0.1039 F cm&minus, 2) when the scan rate was 2 mV s&minus, 1.

Protein transport is an important process of life and is strongly influenced by chiral interaction. But the study of protein transport mainly in biomimetic nanopores, and the application of nanomaterials in biological field only focus on sensors. Inspiring by the excellent property of artificial biomimetic nanochannels, we assembled CdS nanoparticles (CdS NPs) in anodic aluminum oxide (AAO) nanochannels and modified with cysteine enantiomers for bovine serum albumin (BSA) transport to study the improvement of sensitivity about nanomaterials in nanochannels. In addition, we chose a simplified geometric model to explore the BSA transport. The results show that CdS NPs self-assembled in AAO nanochannels and modified with chiral cysteine can improve the sensitivity of BSA response. The theoretical calculation validated CdS NPs self-assembled in AAO nanochannels how to improve the sensitivity of BSA response. This research presents a new application of nanomaterials in biological sensors and is supported by a theoretical calculation, which is meaningful for understanding the role of protein transport.