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Semiconductor photocatalysis technology is a promising method to solve the antibiotics pollution in water. Herein, a series of Sn-doped In2.77S4 (Sn-In2.77S4) hybrid photocatalysts for tetracycline degradation have been fabricated via a one-step hydrothermal process. The analytic results exhibit that doping Sn can improve the photocatalytic performance of In2.77S4 nanosheets under the visible light illumination and the doping amount obviously affects the photocatalytic performance of the samples. When the theoretical molar ratio of Sn4+ to In3+ is 0.04:1 (4%), the photocatalytic efficiency of the Sn-In2.77S4 photocatalyst exhibits the highest of 87.4% in comparison with 39.2% of pure In2.77S4 in 20 min. Moreover, its band gap energy has been reduced to 1.56 eV from 1.75 eV and the light absorption range has been broadened. The transfer rate and separation efficiency of photo-generated electron and hole pairs of the samples have also been enhanced. In addition, the holes play a leading role in the photocatalytic degradation process.

The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer. X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectrometer, UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscope were used to analyze the structure, micro-morphology, chemical compositions, optical properties and photo-generated carrier behaviors of the as-prepared samples, respectively. The photocatalytic degradation mechanism of the as-developed composites was also proposed. Analysis results show SrCO3, an insulator, can improve the photocatalytic performances and recyclability of AgI for degrading tetracycline under visible light. As the theoretical molar ratio of Sr(NO3)2 to AgNO3 increases, the degradation efficiency of the hybrids first increases and then descends. When the theoretical molar ratio of that is 1: 1, it acquires the maximum of 66.6% within 8 min. This is higher than 32.0% of pure AgI and 34.0% of SrCO3. Moreover, after three times degradations it is 63.0%, which is higher than 13.6% of AgI. The improvement of the photocatalytic performance of the sample is attributed to the construction of hybrids. The main activated species in catalysis process are superoxide radicals.

Ag2WO4 is a typically noble metal based photocatalyst with highly efficient photocatalytic activity. However, due to photocorrosion, the pristine Ag2WO4 is prone to inactivation during illumination. Constructing composite photocatalyst may be a useful method to promote the stability of Ag2WO4. In this work, Ag2WO4/graphitic carbon nitride nanotubes (g-C3N4 NTs) composite photocatalyst was prepared by adopting an in-situ composite strategy. The photocatalytic performance of the samples was discussed by the degradation of rhodamine B under visible light, and the catalytic mechanism was also analyzed. The characterization results show that the photocatalytic efficiency of the as-prepared Ag2WO4/g-C3N4 NTs composite increases firstly and then decreases along with the increase of the Ag2WO4 content. When the theoretical molar ratio of Ag2WO4:g-C3N4 NTs reaches 3:2, the photocatalytic degradation efficiency achieves the optimal value, that is 92.4% within 20 min, which obviously exceeds 2.8% of pure Ag2WO4 and 48.9% of pure g-C3N4 NTs. Moreover, the separation and migration efficiency of photoelectron–hole pairs of the composites can be accelerated in comparison with pure samples. In addition, superoxide radicals and hydroxyl radicals play major roles in the photocatalytic degradation process.

The SnO2 quantum dots (SnO2QDs)/ZnS nanosheets (ZnSNs) heterojunction was fabricated via an in-situ synthetic method at room temperature. Rhodamine B, potassium dichromate, and tetracycline were used to discuss the photocatalytic activities of the as-prepared samples under the visible light illumination. The photocatalytic mechanism of the as-prepared samples was also proposed. The experimental results indicate that the degradation efficiency of the as-prepared SnO2QDs/ZnSNs heterojunction first increases and then decreases with increasing the usage of ZnSNs. When the mass ratio of SnO2QDs to ZnSNs is 1: 2 in 180 min, the asprepared samples have the highest degradation efficiency of 89.1% for rhodamine B, 97.7% for potassium dichromate, and 83.8% for tetracycline, which are much higher than 51.7%, 26.8%, and 0.9% of pure SnO2QDs as well as 37.9%, 87.1%, and 19.1% of pure ZnSNs, respectively. After it is repeatedly degraded for 3 times, it possesses the degradation efficiency of 62.5% for rhodamine B, which increases by 200.5% in comparison with 20.8% of the pure SnO2QDs. Moreover, the enhanced photocatalytic performances of the as-prepared hybrids are attributed to the formation of heterojunction between the SnO2QDs and ZnSNs. In addition, hydroxyl radicals and superoxide anion radicals play major roles during the photocatalytic degradation process, while holes play a minor role.

The AgBrO3/few-layer g-C3N4 composite photocatalyst has been developed via an in-situ synthetic method. The structure, morphology, light response range, separation and migration efficiency of the photogenerated electron–hole pairs and element valence state of the as-obtained samples have been characterized. The tetracycline was used to discuss the photocatalytic activities of the samples. The photocatalytic degradation mechanism of the as-obtained composites was also researched. The analysis results show that the photocatalytic degradation property of the asobtained composite photocatalyst appears to the tendency of first increasing and then decreasing with increasing the amount of AgBrO3 under visible light illumination. When the mass ratio of AgBrO3 to g-C3N4 is 4:3, in 60 min, the photocatalytic degradation efficiency of the as-obtained composites reaches the maximum of 79%. It is 37% and 45% higher than that of pure AgBrO3 and g-C3N4, respectively. Moreover, the separation and migration efficiency of the photogenerated electron–hole pairs of the as-prepared composites are also enhanced. In addition, superoxide radicals and holes are the dominant active species during the photocatalytic degradation process.

The AgBrO₃/few-layer g-C₃N₄ composite photocatalyst has been developed via an in-situ synthetic method. The structure, morphology, light response range, separation and migration efficiency of the photogenerated electron-hole pairs and element valence state of the as-obtained samples have been characterized. The tetracycline was used to discuss the photocatalytic activities of the samples. The photocatalytic degradation mechanism of the as-obtained composites was also researched. The analysis results show that the photocatalytic degradation property of the asobtained composite photocatalyst appears to the tendency of first increasing and then decreasing with increasing the amount of AgBrO₃ under visible light illumination. When the mass ratio of AgBrO₃ to g-C₃N₄ is 4:3, in 60 min, the photocatalytic degradation efficiency of the as-obtained composites reaches the maximum of 79%. It is 37% and 45% higher than that of pure AgBrO₃ and g-C₃N₄, respectively. Moreover, the separation and migration efficiency of the photogenerated electron-hole pairs of the as-prepared composites are also enhanced. In addition, superoxide radicals and holes are the dominant active species during the photocatalytic degradation process.

Visible-light-driven WO3and#183;0.33H2O/Ag2MoO4 composites have been prepared by using an in-situ growth of Ag2MoO4 nanoparticles on the surfaces of WO3and#183;0.33H2O. The photocatalytic activities of the samples were studied by degradation of rhodamine B and levofloxacin dilute solution. The synergistic photocatalytic mechanism was also analyzed. Experimental results reveal that the as-developed hybrids have higher photocatalytic activity than pure samples. When the theoretical molar ratio of WO3and#183;0.33H2O to Na2MoO4and#183;2H2O is 1:0.15, the as-developed hybrids have the highest photocatalytic degradation efficiency of 99.0% for rhodamine B in 45 min and 40.9% for levofloxacin in 120 min. Furthermore, there are chemical bonds between WO3and#183;0.33H2O and Ag2MoO4. In addition, the super oxide radicals play the leading role during the photocatalytic degradation process of the samples. This work will provide reference for treatment of organic dyes and antibiotics pollution in water with using solar energy.

In this study, we prepared gold nanoparticles by electrochemical synthesis and inlaid in the photo-electrode of dye-sensitized solar cells (DSSCs) to study the surface plasma resonant (SPR) and light-scattering effects on the properties of dye-sensitized solar cells. The analyses of field emission scanning electron microscopy (FE-SEM) show that the average diameter of gold nanoparticles is 50nm. The results of ultraviolet-visible absorption spectra show that the absorption wavelength is about 533nm for gold nanoparticles. The conversion efficiency with different amounts of gold nanoparticles in TiO2 photo-electrodes is 5.42%, 5.92%, 6.06%, and 5.51% with the amounts of 0µL, 300µL, 400µL, and 500µL, respectively. The best conversion efficiency of the dye-sensitized solar cells with gold nanoparticles added is 6.06%, and is higher than that the cells without gold nanoparticles, which is 5.42%. In addition, in order to study light-scattering effects on the photo-electrode, different thicknesses of large particle size TiO2 (~250nm) coated onto photo-electrode to form double layer structure. The best conversion efficiency of the dye-sensitized solar cells with gold nanoparticles added and with the thickness of 3.3µm light scattering layer is 7.10%, which is higher than that of the cell without light-scattering layer, which is 6.06%. This result indicates that the effect of gold nanoparticles on the photo-electrode can increase the conductivity and reduce the recombination of charges in the photo-electrode, and the light-scattering structure can enhance light transmission path in TiO2 films and the absorption of photons in the photo-electrode, resulting in the increase of the photoelectric conversion efficiency for DSSCs. The addition of gold nanoparticles leads to a linear increase in conversion efficiency of the DSSC. When the volume of added gold nanoparticles is 500µL, the Jsc begins to decrease.Display Omitted The effect of gold nanoparticles can increase the conductivity and reduce the recombination of charges in the photo-electrode.The light-scattering structure can enhance light transmission path in TiO2 films and the absorption of photons.Gold nanoparticles result in the increase of the photoelectric conversion efficiency for DSSCs.

It remains a great challenge to overcome the problems of poor conductivity and rapid charge recombination in bismuth oxybromide (BiOBr). Herein, for the first time we report the synergistic effect of oxygen vacancies (Ov) and p-n heterojunction to improve photoelectrochemical performance of BiOBr. Benefitting from the new electron donor level caused by oxygen vacancies, the visible-light absorption region, carrier concentration and exposure of {001} facets of BiOBr are all increased. In the meantime, the 2D p-n heterojunction between BiOBr and BiOI leads to a built-in electric field and thus significantly accelerating the charge separation and transfer. Upon visible light irradiation, the resulted BiOBr-Ov/BiOI photoanode presents robust photoelectrochemical performance, achieving a photocurrent density of 1.33 mA/cm2 at 1.23 V vs. RHE. This work not only provides new insight for designing efficient photoelectrodes but also highlights the importance of oxygen defect-engineering strategy in photoelectrochemical water splitting.

In this study the metal-semiconductor-metal (MSM) structure ultraviolet (UV) photodetectors (PDs) based on Mg"xZn"1"-"xO thin films were fabricated. The Mg"xZn"1"-"xO thin films were grown on glass substrates by sol-gel method. The results show that the optical absorption has a blue shift and higher transmittance with increasing Mg dopant. The optical band gap were modified by 3.28-3.52eV, which corresponded to x=0 and x=0.16. For a 10V applied bias, the dark currents of the Mg"xZn"1"-"xO MSM-PDs were 637nA (x=0) to 0.185nA (x=0.16) and showed good Schottky contacts. This UV-visible rejection ratio of the Mg"xZn"1"-"xO UV PDs at x=0, 0.16, 0.21 and 0.33 were 18.82, 35.36, 40.91 and 42.92, respectively.

ZnO nanorod arrays were synthesized by chemical-liquid deposition techniques on Mg x Zn 1− x O ( x = 0, 0.07 and 0.15) buffer layers. It is found that varying the Mg concentration could control the diameter, vertical alignment, crystallization, and density of the ZnO nanorods. The X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) data show the ZnO nanorods prefer to grow in the (0 0 2) c -axis direction better with a larger Mg concentration. The photoluminescence (PL) spectra of ZnO nanorods exhibit that the ultraviolet (UV) emission becomes stronger and the defect emission becomes weaker by increasing the Mg concentration in Mg x Zn 1− x O buffer layers.