Preparation of 2D square-like Bi2S3-BiOCl heterostructures with enhanced visible light-driven photocatalytic performance for dye pollutant degradation

A series of Bi2 S3-BiOCI composites with two-dimensional(2 D) square-like structures were prepared via a two-step anion exchange route.X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and diffuse reflectance spectra(DRS)were used to investigate the properties of the as-prepared Bi_2 S_3-BiOCI heterostructures. The coupling of BiOCl and Bi_2 S_3 induced enhanced photoabsorption efficiency and bandgap narrowing. A reactive brilliant red X-3 B dye was used as a contaminant to test the photocatalytic activity of the obtained Bi_2 S_3-BiOCl samples under visible light irradiation. The sample Bi_2 S_3-BiOCl with a mass ratio of 8:4 exhibited the highest photodegradation efficiency, which was six times higher than that of pure BiOCl. In addition, a mechanism for the enhancement of photocatalytic activity is proposed.

Fabrication of Bi_2WO_6 quantum dots/ultrathin nanosheets 0D/2D homojunctions with enhanced photocatalytic activity under visible light irradiation

A novel visible light‐responsive homogeneous catalyst based on Bi2WO6 quantum dots(QDs‐BWO)/Bi2WO6 nanosheets(N‐BWO)was successfully fabricated through a simple hydrothermal method.A variety of techniques were employed to investigate the morphology,structure,and electronic properties of the samples.The photocatalytic performance of the QDs/N‐BWO materials was investigated by monitoring the degradation of 4‐chlorophenol and rhodamine B under visible light irradiation.The as‐fabricated QDs/N‐BWO materials showed higher photocatalytic activity than both QDs‐BWO and N‐BWO.The results reveal that the incorporation of the QDs improved the separation efficiency of electron‐hole pairs,leading to enhanced photocatalytic activity.Moreover,the results of quenching experiments show that·O2– species played a major role in the degradation process.This work provides an important reference for the fabrication of homogeneous catalysts with high performance in the degradation of different types of pollutants.

Synergistic effects of CdS in sodium titanate based nanostructures for hydrogen evolution

In this paper, nanotubes and nanoribbons of sodium titanate structures were synthesized via hydrothermal methods in alkaline solution. CdS decorated titanate nanotubes and nanoribbons were therefore constructed for exploring the performance of hydrogen evolution and synergistic effect of CdS based titanate structures. CdS decorated titanate nanotubes and nanoribbons were characterized by high resolution transmission electron microscopy （HRTEM）, X-ray diffraction （XRD）, UV-vis, Brunauer- Emmett-Teller （BET） and X-ray photoelectron spectroscopy （XPS） measurements. CdS encapsuled in titanate nanotubes （CdS-ETNTs） showed the best capacity of H2 evolution by water splitting and stability than that from the other two structures, i.e., CdS doped titanate nanotubes （CdS-DTNTs） and CdS doped titanate nanoribbons （CdS-DTNRs）, which could be explained by the synergistic effect of decorated CdS with sodium titanate structures and confinement effect of CdS nanoparticles encapsuled inside

Effect of coating modification of cordierite carrier on catalytic performance of supported NiMnO_3 catalysts for VOCs combustion

NiMnO3 perovskite catalysts supported on cordierite modified by CexZr（1-x）O2 coatings were prepared using impregnation and sol-gel methods for catalytic combustion of single/double component VOCs at different concentrations and GHSV of 15,000 h^（-1）, which were characterized by BET, XRD, SEM, FT-IR, H2-TPR and O2-TPD. After coating modification, the specific surface area of catalysts is improved obviously.Among the catalysts, the Ce（0.75）Zr（0.25）O2 coating modified NiMnO3 catalyst exhibits the best catalytic activity for VOCs combustion with 95.6% conversion at 275 ℃ and has stable activity when catalyst is embalmed at 800 ℃. In addition, the catalyst also presents the excellent water-resistant and conversion stability over time-on-stream condition. The reason is that Ce（0.75）Zr（0.25）O2 coating can promote more lattice distortion and defects and smaller crystal size, which improve oxygen transfer capability and dispersion of active component.

Dual Z-scheme Bi_(3)TaO_(7)/Bi_(2)S_(3)/SnS_(2)photocatalyst with high performance for Cr(Ⅵ)reduction and TC degradation under visible light irradiation

Ternary direct dual Z-scheme Bi_(3)T_(a)O_(7)/Bi_(2)S_(3)/SnS_(2) photocatalyst was successfully prepared by hydrothermal method.The composite photocatalysts exhibited high photocatalytic performance on both Cr(Ⅵ)reduction and tetracycline(TC)degradation under the irradiation of visible light.The results manifested that the photogenerated charge transfer efficiency was improved after forming the dual Z-scheme heterojunction.As a result,the composite catalysts exhibited higher photocat-alytic degradation efficiency than the corresponding single samples.The apparent rate constant(k)value of the best sample BBS-3 for TC degradation was 0.0403 min^(-1),which was 40 times,8 times,and 18 times higher than that of single samples.While the k value of BBS-3 for the Cr(Ⅵ)reduction was 0.0249 min^(-1),it was about 23 times,7 times,and 18 times that of single catalysts.Recycle experiments indicated that the BBS-3 had good photocat-alytic stability.Meanwhile,the possible mechanism on Cr(Ⅵ)reduction and TC degradation was proposed based on the experimental results.

Highly efficient Zr doped-TiO_2/glass fiber photocatalyst and its performance in formaldehyde removal under visible light

Zr-doped-TiO2 loaded glass fiber（ZT/GF） composite photocatalysts with different Zr/Ti ratios were prepared with a sol–gel process. Zr4＋can replace Ti4＋in the TiO2 lattice, which is conducive to forming the anatase phase and reducing the calcination temperature. The glass fiber carrier was responsible for better dispersion and loading of Zr-doped-TiO2 particles, improving the applicability of the Zr-doped-TiO2. The ZT/GF photocatalysts were characterized by X-ray diffraction（XRD）, scanning electron microscope（SEM）, Fourier transform infrared spectroscopy（FT-IR）, ultraviolet–visible spectroscopy（UV–vis） and Barrett–Joyner–Halenda（BJH）. The performance of photocatalysts with different loading was evaluated in formaldehyde degradation under visible light at room temperature. ZT/GF0.2exhibited the highest activity, with a formaldehyde removal rate as high as 95.14% being observed, which is better than that of the photocatalyst particles alone. The stability of the catalyst was also tested, and ZT/GF exhibited excellent catalytic performance with 94.38%removal efficiency, even after seven uses.