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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 CdS/ spherical g-C3N4 n-n heterojunction photocatalyst was fabricated via a solvothermal method. The tetracycline was used to characterize the photocatalytic properties of the as-developed hybrids. The photocatalytic degradation mechanism of the as-developed heterojunction photocatalyst was also analyzed. Research results show that CdS nanoparticles are well dispersed in the surface layer of spherical g-C3N4. Moreover, the mass ratio of CdS to spherical g-C3N4 will influence the photocatalytic activity of the asdeveloped composites, which shows the trend of first increasing and then decreasing as it increased. When the mass ratio is 7:1, in 25 min, the as-developed heterojunction shows 93.2 % of the maximum photocatalytic efficiency and still exhibits 83.6 % after 5 times cycle testing. Moreover, the as-developed hybrids can accelerate the electron transport and improve the separation efficiency of photo-generated carriers compared with pure samples. In addition, the holes and superoxide radicals are dominating active species during the photocatalytic degradation process.

The Zn0.5Cd0.5S/SnO2 composite photocatalyst was synthesized via a hydrothermal method. The crystal phase, micromorphology, optical and photoelectric property as well as surface elements valence were characterized using X-ray diffraction, field emission scanning electron microscope, transmission electrical microscope, UV–Vis diffuse reflectance spectrometer, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, respectively. Tetracycline was used to discuss the photocatalytic properties of the samples under visible light irradiation. Research results indicate that the as-synthesized Zn0.5Cd0.5S/SnO2 composite photocatalysts show better photocatalytic performance than that of pure samples. Moreover, the photocatalytic activity of the as-synthesized composites presents first increased and then decreased with increasing the amount of SnO2 in the composites. When the quality ratio of SnO2 to Zn0.5Cd0.5S is 7%, in 60 min, the as-synthesized composites reveal the best photocatalytic degradation efficiency of 92.9%, which is high than 85% of Zn0.5Cd0.5S and 0% of SnO2. This is ascribed of the improvement of the separation efficiency of photo-generated electron–hole pairs and the transmission rate of electrons. Furthermore, the decomposition mechanism of as-synthesized composites for tetracycline was also provided. The holes and superoxide radicals play crucial species in the photocatalytic degradation process.

SnO2/AgIO4 hybrids were fabricated by an in-situ synthetic method at room temperature. The structure, morphology, light response range, separation efficiency of the electron-hole pairs and elements of the as-synthesized samples were characterized by adopting X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, respectively. The synergistically photocatalytic degradation mechanism of the as-synthesized composites was also proposed. The experimental results reveal that under the visible light irradiation the as-synthesized SnO2/AgIO4 hybrids can enhance the photocatalytic degradation efficiency of rhodamine B compared to pure samples. With increasing the molar ratios of AgIO4 to SnO2, it displays the trend of first increasing and then decreasing. When it is 1:2 in 150 min, the as-prepared hybrids have the highest degradation efficiency of 93.1%, which increases by 6550.0%, 30.5%, and 1505.0% compared to those of pure SnO2, AgIO4, and TiO2 (P25), respectively. Moreover, the Sn-O-Ag cross-linking bonds are formed at the interfaces of SnO2 and AgIO4. In addition, superoxide anion radicals and holes play a major role in the process of photodegradation.

The yolk–shell Bi@void@SnO2 photocatalyst was synthesized via a step-by-step process. The composition, morphology, optical and photoelectrochemical properties as well as the surface chemical composition and states of the samples were characterized by X-ray diffraction, transmission electron microscopy, UV–Vis diffuse reflectance spectra, electrochemical impedance spectra and X-ray photoelectron spectrometer, respectively. The tetracycline has been used to evaluate the photocatalytic activities of the as-synthesized samples. Compared with the degradation efficiency of 16.33% for pure Bi and almost nothing for SnO2 under visible light irradiation, the as-developed Bi@void@SnO2 photocatalyst possesses 81.81% of degradation efficiency. Meanwhile, the light absorption of the as-developed yolk–shell composites is broadened from ultraviolet to visible light comparing to pure SnO2 due to the surface plasmon resonance effect of Bi spheres. Moreover, the superoxide radicals, especially in holes, play leading roles during the photocatalytic degradation process. In addition, the decomposition mechanism of the as-fabricated composites for tetracycline is analyzed in detail.

Zn2SnO4/few-layer boron nitride nanosheets (FBNNS) hybrids were synthesized via a one-step hydrothermal method. The structures, morphology, optical properties, electron transformation and separation of the as-prepared products were characterized by X-ray diffraction, transmission electrical microscopy, UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscopy, respectively. Rhodamine B was used to evaluate the photocatalytic activities of the as-prepared samples under visible light illumination. The photocatalytic mechanism was also explored. Experimental results showed that the degradation efficiency of rhodamine B was firstly increased and then decreased with increasing the usage amount of FBNNS. When it was 9 wt% based on the weight of Zn2SnO4, the degradation efficiency of the as-prepared Zn2SnO4/FBNNS-9 wt% composites reached to the maximum of 97.5% in 180 min, which was higher than 39.2 % of pure Zn2SnO4. Moreover, the holes played mainly active roles in photocatalytic reaction process. In addition, the as-prepared hybrids could enhance the separation efficiency of photoexcited carriers compared to pure Zn2SnO4.

The AgI/2D-La2Ti2O7 hybrids were obtained via a facile method at room temperature. Rhodamine B, as an organic dye, was used to determine the photocatalytic activity of the samples. The photocatalytic degradation mechanism was also analyzed. Experimental results display that AgI can broaden the light absorption of La2Ti2O7 under the visible light irradiation. The photocatalytic degradation efficiency of the as-synthesized hybrids appears the tendency of first increasing and then decreasing with increasing the usage of La2Ti2O7. When the usage of La2Ti2O7 is 10%, within 60 min, the as-synthesized hybrids possess the maximum of 93.1%. This is higher than 2.1% of La2Ti2O7 and 80.9% of AgI. Moreover, the improved photocatalytic activity can be attributed to AgI particles conjugating with 2D-La2Ti2O7 nanosheets via chemical-bonds, which can enhance the separation and transformation of the photo-generated holes and electrons. In addition, the dominating role is superoxide radicals during the photocatalytic process.

In the present work, wrinkled n-type WS2 nanosheets were synthesized and then used to construct the In2.77S4/WS2 p-n heterojunction photocatalyst. Experimental results reveal that the as-prepared hybrids present excellent photocatalytic activity for Cr(VI) reduction and tetracycline oxidation under visible and infrared light irritation. The photocatalytic efficiency of the as-prepared catalysts is found to increase initially followed by the decrease with the more weight content of WS2. When WS2 is up to 4 wt%, the as-prepared photocatalysts exhibit the highest photocatalytic activity, and are capable of reducing 99.1% of Cr(VI) in 60 min and oxidizing 87.5% of tetracycline in 20 min, much higher than 86.6 and 40.0% of pure In2.77S4, respectively. This enhanced photocatalytic activity is attributed to the construction of In2.77S4/WS2 p-n heterojunction between p-In2.77S4 and n-WS2. The detailed clarification of photocatalytic mechanism is also elaborated in the paper.

Full-spectrum-responsive AgI/WS2 composites as an efficient photocatalyst have been synthesised by an in-situ growth of AgI on the surfaces of WS2 nanosheets. The photocatalytic activities of the samples were evaluated by degradation of rhodamine B dilute solution under visible light irradiation. Experimental results showed that the introduction of WS2 nanosheets could enhance light absorption, photocatalytic activity, and recyclability of the pure AgI in the region of visible and infrared light. Moreover, the degradation efficiency of the as-synthesised AgI/WS2 composites exhibited the trend of first increased and then decreased with increasing the amount of WS2 nanosheets. When the usage of WS2 nanosheets was 7 wt%, the as-prepared composites possessed the maximum of 91.2% in 30 min. Furthermore, after three cycles of degradation, it could still degrade 89.0% of rhodamine B, obviously higher than 11.4% of pure AgI. In addition, a possible degradation mechanism of the as-synthesised AgI/WS2 hybrids was provided.

The Ag2CrO4/SnO2 n–n type heterojunction has been fabricated by coupling Ag2CrO4 particles with SnO2 nanorods via an in situ synthetic method. The photocatalytic degradation mechanism of the as-prepared heterojunction has also been discussed. Characterization results revealed that the as-fabricated Ag2CrO4/SnO2 composites could reinforce the photo-degradation competencies for rhodamine B dilute solution compared to pure Ag2CrO4 and SnO2 samples. As the increase in the molar ratios of Ag2CrO4–SnO2, the photocatalytic degradation efficiency appeared to the tendency of first increasing and then decreasing. When it was 4:10, in 90 min, the as-obtained samples possessed the vintage photocatalytic degradation efficiency of 95.8% among of pure SnO2, Ag2CrO4 and the as-prepared composites with various molar ratios, respectively. Furthermore, the Ag2CrO4 and SnO2 were connected via chemical bonds to form the homogenous heterojunction. It could boost the separation and transfer of the photogenerated holes and electrons. In addition, the holes, hydroxyl and superoxide radicals played a major role during the photodegradation process.

A novel AgCl/AgIO4 composite was fabricated via an in-suit synthetic method. The as-prepared samples have been characterised by using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. Rhodamine B dilute solution was used to discuss the photocatalytic activities of the as-prepared composites under the visible light irradiation. Experimental results showed that with increasing the contents of AgIO4 the photocatalytic activity of the as-prepared hybrids was first increased and then decreased. When the molar ratio of AgCl to AgIO4 was 1:5, in 30 min, the as-prepared composites with the bandgap of 1.21 eV exhibited the highest photocatalytic activity and possessed 96.3% of degradation efficiency. That was increased by 71.5 and 27.9% compared with AgCl and AgIO4, respectively. Moreover, AgCl was linked with AgIO4 via chemical bonds rather than physical contact at the interfaces of these two semiconductors. In addition, a possible photocatalytic degradation mechanism for the as-prepared hybrids was also presented.

The direct Z-scheme Ag2WO4/WS2 photocatalysts had been fabricated by using a deposition method. Experimental results indicated that WS2 nanosheets could improve the photocatalytic activity, light absorption and recyclability of Ag2WO4 under the visible light irradiation. The degradation efficiency of the as-obtained Ag2WO4/WS2 hybrids for rhodamine B displayed first increasing and then decreasing with increasing the usage of WS2 nanosheets. When the usage of WS2 was 15 wt%, in 120 min, it reached the maximum of 97.8%, which was higher than 17.8% of pure Ag2WO4. Moreover, after three cycles of the degradation, the as-prepared hybrids still possessed 94.4% of the degradation efficiency, which increased by 1211.1% compared with pure Ag2WO4. Moreover, superoxide and hydroxyl radicals played major role during the process of photocatalytic degradation. The enhanced photocatalytic activity could be ascribed to the formation of direct Z-scheme photocatalytic system between Ag2WO4 and WS2.

The nanosized Bi-doped SnO2/reduced graphene oxide 3D hybrids have been synthesized via one-step hydrothermal method. The structures, morphologies, photocatalytic activities of the as-prepared samples were discussed, respectively. The formation mechanism of the as-prepared hybrids was also proposed. Experimental results indicated that the usage amount of Bi2Sn2O7 obviously affected the photocatalytic performance of the as-prepared products. When it was 450 mg, the as-prepared sample possessed the band gap energy of 1.9 eV and the photocatalytic efficiency of 90% in 210 min for degradation of rhodamine B solution. In addition, triethylene tetramine and the as-prepared carbon hydrogel could act as reductant to synergistically reduce Bi2Sn2O7 into Bi-doped SnO2 particles during the formation of the hybrids.

Visible and near-infrared light responsed Sn1−x Bi x S2nanosheets was synthesised via a simple hydrothermal method. Rhodamine B was adopted to evaluate the degradation efficiency of the as-prepared samples. Experimental results showed that the doping content of Bi3+ could obviously affect the degradation efficiency of SnS2. It was first increased and then decreased with increasing the Bi3+ content under the visible light irradiation. When the mole fraction of doping Bi3+ was 5%, the as-prepared Sn0.95Bi0.05S2 with a bandgap of 0.38 eV had the highest degradation efficiency of 95.9% in 120 min. Moreover, the as-prepared composites possessed more effective electron–hole pair separation than that of pure SnS2. In addition, a possible degradation mechanism of the as-prepared Sn0.95Bi0.05S2 was proposed.

Novel p-n heterojunction of Bi2Sn2O7-Ag2CrO4 photocatalysts with various contents of Bi2Sn2O7 were in-situ synthesized at 25 °C. X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflectance spectra, photoluminescence emission and electrochemical impedance spectra were employed to characterize the as-prepared samples. Experimental results showed that, under the visible light irradiation, with increasing the amount of Bi2Sn2O7, the degradation efficiency of the as-prepared hybrids was first increased and then decreased. It possessed the highest degradation efficiency of 97.5 % for rhodamine B in 120 min, which was obviously higher than that of 76.7 % of Ag2CrO4 and 11.8 % of Bi2Sn2O7, respectively. Moreover, it possessed the degradation efficiency of 90.4 % for methyl orange and 99.8 % for methylene blue. In addition, after it was circulated for 5 times, the as-prepared hybrids still possessed the degradation efficiency of 90.2 % for rhodamine B, which increased by 240.4 and 1950.0 % in comparison with Ag2CrO4 and Bi2Sn2O7, respectively. The enhanced photocatalytic activity could be attributed to the formation of the p-n heterojunction at the interface of p-Bi2Sn2O7 and n-Ag2CrO4.

Zn2SnO4-reduced graphene oxide photocatalysts were synthesized by using SnCl4 5H2O, Zn(NO3)2 · 6H2O and graphene oxide via hydrothermal process. The structure, morphology, specific surface area and photo response of the as-prepared nanocomposites were characterized by X-ray diffraction, Transmission electron microscopy, UV-vis diffuse reflectance spectra, Brunauer-emmett-teller surface area measurement and Photoluminescence emission spectra. Experimental results showed that the Zn2SnO4 nanoparticles, with 20-30 nm a size range, were uniformly dispersed on the surfaces of reduced graphene oxide. Moreover, the as-prepared Zn2SnO4-reduced graphene oxide photocatalysts exhibited enhanced photocatalytic activities for degradation of Rhodamine B compared to those of pure Zn2SnO4. When the amount of reduced graphene oxide was 4 wt%, it showed the highest photocatalytic efficiency of 99.7% for 240 min, and the photocatalytic efficiency was still 98.5% after it was recycled 4 times. It also possessed the band gap of 2.48 eV and specific surface area of 58.1 m2 g-1.

Hexagonal boron nitride was adopted as a heterogeneous nucleation agent to fabricate polyamide 6 based nanocomposite films via a solution casting method. Isothermal crystallization behaviors of the...

Boron nitride nanoparticles were prepared in a muffle furnace at 1000 °C by using commercial available boron nitride flakes and sodium chloride as raw materials. The structure, functional groups, morphology and specific surface area of the as-prepared samples were characterized by X-ray diffracmeter, fourier-transform infrared spectrometer, transmission electron microscope and accelerated surface area/porosimetry system, respectively. In order to evaluate the properties of the as-prepared products, they were mixed with epoxy resin to fabricate polymer-based composites. Experimental results showed that the average size and specific surface area of the as-prepared nanoparticles were about 20 nm and 895.7 m2/g. Moreover, the as-prepared nanoparticles could improve the tensile strength and elongation at break of the epoxy matrix. Both of them were first increased and then decreased with increasing the usage amount of the as-prepared nanoparticles. When the usage amount of the boron nitride nanoparticles was 0.4 wt%, the tensile strength and elongation at break of the composites reached to 71.4 MPa and 22.1%, which were the maximum values of the composites, respectivley. They were increased by 137 and 146% more than those of pure epoxy resin. In addition, the as-prepared fillers could accelerate the solidification of the matrix.

Large-scale exfoliated boron nitride nanosheets were achieved via a liquid exfoliation sonication method by using sodium fluoride and ammonium hydroxide as Lewis base compounds. The crystal structure, surface functional groups, morphology and thickness of the as-prepared samples were characterized by X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and atomic force microscopy, respectively. The as-prepared samples were introduced into epoxy resin to fabricate the polymer-based composites. Experimental results showed that the layer thickness of the as-prepared nanosheets was in the range of 1 to 3 layers. Moreover, it could improve the tensile properties of the matrix. When the loading of the as-prepared nanoparticles was 0.4 wt%, the tensile strength and elongation at break of the composites reached to their maximum values 65.6 MPa and 25.9%, which were increased by 118% and 192% more than that of pure resin. In addition, the as-prepared boron nitride samples could improve the thermostability and promote the curing of the matrix.

Hexagonal boron nitride nanosheets were mixed with polyamide 6 to fabricate polymer-based composites by using a solution blending method. The nonisothermal crystallization behaviors of the as-prepared composites were investigated via differential scanning calorimetry. Results showed that the peak temperature of the exothermic crystallization curve was moved to lower temperature with increase in the cooling rate. At the same cooling rate, the peak temperature of the pure polyamide 6 was lower than those of the composites. Moreover, the crystallization rate increased gradually with increase in the cooling rate. In addition, at the cooling rates of 5 or 10°C min−1, the crystallization rate of pure polyamide 6 was higher than those of all compositions of the composites. However, at the cooling rates of 20 or 40°C min−1, the crystallization rate decreased first and then increased with increase in the fillers loading. The crystallization mechanism was between one-dimensional and two-dimensional during t...

The Zn2+ doped In2.77S4 (Zn–In2.77S4) photocatalyst has been synthesized via a one-step hydrothermal method. The tetracycline was adopted to measure the photocatalytic performance of the as-fabricated Zn–In2.77S4 composites. The probable photocatalytic degradation mechanism of the as-prepared composites was also discussed. Experimental results reveal that doping Zn2+ into In2.77S4 can broaden the light absorption range and improve the recycle ability as well as the separation efficiency of photo-generated electron–hole pairs of pure In2.77S4. Moreover, as the doping amount of Zn2+ increased the photocatalytic efficiency of the as-obtained Zn–In2.77S4 composites appears the tendency of firstly increasing and then decreasing. When the molar ratio of Zn2+ to In3+ is 0.04:1 (4%), in 15 min, the photocatalytic efficiency of the as-developed Zn–In2.77S4 photocatalyst reaches to the maximum of 90.0%. It is higher than 31.8% of pure In2.77S4. Furthermore, superoxide radicals and holes play major roles in the process of photodegradation tetracycline. This research can supply a promising guide to solve antibiotics pollution in water under sunlight.

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.

The In2.77S4/SrCO3 heterojunction photocatalyst had been prepared by one-step hydrothermal method. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrometry, UV–Vis diffuse reflectance spectroscopy and electrochemical impedance spectroscopy were used to analyze the structure, morphology, chemical compositions, optical properties and charge carrier behaviors of the as-prepared In2.77S4/SrCO3 hybrids, respectively. Experimental results revealed the SrCO3 could obviously improve the recyclability and photocatalytic activities of In2.77S4 nanosheets for both methyl orange and tetracycline oxidation under visible light. The photocatalytic degradation efficiency of the as-obtained In2.77S4/SrCO3 hybrids was first increased and then decreased with increasing the molar ratio of Sr(NO3)2 to In(NO3)3·4.5H2O. When it was 0.4:1, that of the as-prepared hybrids with the band gap of 1.63 eV reached the maximum of 96.0% in 30 min for methyl orange and 82.7% in 20 min for tetracycline. These were higher than 88.0% and 40.0% of In2.77S4 nanosheets as well as 0.8 and 1.8% of SrCO3 particles, respectively. After three cycles, its photocatalytic efficiency still possessed 92.7% for methyl orange and 80.3% for tetracycline, which were much higher than 35.3% and 11.3% of In2.77S4 nanosheets. Moreover, the possible photocatalytic degradation mechanism of the In2.77S4/SrCO3 hybrids was also proposed.

Zinc oxide/reduced graphene oxide composites with various morphologies and properties were prepared via a one-step solvothermal process. The formation of zinc oxide and reduction of graphene oxide were simultaneously accomplished. These as-obtained samples showed high performance in removing methylene blue from aqueous solution. Solvent could play an important role in tuning the morphologies of the zinc oxide and the efficiency of the final composites. Composites prepared in acetone showed the highest removal efficiency, compared with those prepared in water and ethanol. Loading content of the reduced graphene oxide could affect the performance as well. With the increase in the content of the reduced graphene oxide, the as-prepared samples showed enhanced performance gradually. The as-prepared composite showed certain stability, with a maximum recyclability of 5 times for efficient removal. The effective removal of target dye turned out to be the result of the combination of physical adsorption and photo-catalysis.

SnS2/few layer boron nitride nanosheets composites were synthesized via a one-step hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, transmission electrical microscopy, UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, photoluminescence emission spectra and electrochemical impedance spectroscopy, respectively. Rhodamine B was adopted to evaluate the degradation efficiency of the as-prepared samples under visible light irradiation. Experimental results showed that, compared to pure SnS2, the few layer boron nitride nanosheets could improve photocatalytic activities of the samples for the degradation of Rhodamine B. With increasing the usage amount of the few layer boron nitride nanosheets, the degradation efficiency was first increased and then decreased. When the usage amount of the few layer boron nitride nanosheets was 10 wt%, it exhibited the highest degradation efficiency of 93.7% in 210 min, which was higher than 50% of pure SnS2. After it was recycled for four times, it still possessed 88.7% of degradation efficiency. This was increased by 1008.7% than pure SnS2. Moreover, it had band gap energy of 1.78 eV, obviously smaller than 2.06 eV of pure SnS2. In addition, a possible photocatalytic mechanism was also presented.

Nanosized Ag2CrO4/few layer boron nitride composites were prepared via in situ precipitation method. The crystal structure, morphology, optical properties, and charge carrier behavior were investigated by X-ray diffraction, transmission electrical microscopy, UV-vis diffuse reflectance spectroscopy, and electrochemical impedance spectroscopy, respectively. The photocatalytic activities of the as-prepared hybrids were discussed by degradation of rhodamine B under visible-light irradiation. Experimental results showed that the average size of pure Ag2CrO4 particles was about 20 nm. Moreover, the degradation efficiency of the as-prepared hybrids was first increased and then decreased with increasing the usage amount of few layer boron nitride nanosheets. When it was 10 wt%, in 120 min, the degradation efficiency of the as-prepared hybrids had reached the maximum of 96.7%. It was much higher than 75% of pure Ag2CrO4 nanoparticles. After 3 cycles of the degradation, the efficiency of the as-prepared composites was decreased from 96.7 to 91.8%. Trapping experiment results revealed that holes played a major role during the photocatalysis process. In addition, electrochemical impedance spectroscopy results indicated that few layer boron nitride nanosheets could enhance the separation and transfer of photogenerated electrons and holes.