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Oxygen vacancy-rich Bi/Bi 3 TaO 7 binary nanomaterials were obtained by a simple in situ reduction. The as-prepared composite exhibited superior photocatalytic activity for the degradation of RhB compared to the single material under the visible light range. The degradation rate of the optimal sample reached 92% within 120 min, 12.25 times that of the pure Bi 3 TaO 7. XRD and HRTEM characterization showed that the Bi metal obtained through in situ reduction was loaded on the Bi 3 TaO 7 nanostructure. In addition, XPS and EPR indicated a significant increase in the oxygen vacancy content of the composites. The time-resolved transient fluorescence spectroscopy and photocurrent results proved that the separation rate of photoexcited carriers and the corresponding ability of photoelectrons are greatly increased. It is due to the synergistic effect of the unique photo-reaction excitation pathway induced by bismuth metal plasma resonance and oxygen vacancies, which not only extends the photo-reaction to the infrared region but also increases the carrier residence time, and this is the fundamental reason for the excellent photocatalytic performance of the composite material. The h+ is the main reactive radical of the reaction, and •O 2 − also plays a role. Based on the above characterization study, we propose a possible photoreaction mechanism for the synergistic oxygen vacancy and Bi metal of Bi/Bi 3 TaO 7. Construction of Bi/Bi 3 TaO 7 photocatalysts enriched with oxygen vacancies by in situ reduction. The synergistic effect of plasmon resonance effect of metallic Bi and the unique photo-reaction excitation pathway induced by oxygen vacancies greatly improves the photocatalytic performance. [Display omitted] • In situ reduction synthesis of Bi 3 TaO 7 photocatalysts with Bi metal loading and abundant oxygen vacancy defects. • Unique material design enables an extended light response range and fast electron transfer. • The composite photocatalytic material showed excellent degradation effect on RhB and MB. • Efficient synergy of Bi metal and oxygen vacancies is profoundly elucidated. • This work provides an innovative pathway for the structural design of practical Bi-based photo-catalysts. [ABSTRACT FROM AUTHOR]

In the study, Z-scheme CdS/BiOCl visible light reactive photocatalysts were prepared by a one-step synthesis. The composition, morphology, optical absorption property and degradation mechanism of as obtained binary composites were investigated in detail. SEM, TEM and XPS observation indicated that CdS nanoparticles were well dispersed on BiOCl nanosheets and bounded chemically to BiOCl. The CdS/BiOCl composite photocatalysts showed the enhanced photocatalytic performance on degrading RhB under visible light irradiation. Among them, 5-CdS/BiOCl exhibited the highest degradation rate (up to 94%), which was 1.9 and 4.7 times higher than those of CdS and BiOCl, respectively. And the performance of 5-CdS/BiOCl photocatalyst remained stable after four replicate experiments. The prime causes for the improved capability of CdS/BiOCl photocatalysts were their low carrier recombination and extended light response range. A feasible Z-scheme heterojunction mechanism was revealed according to radical capture experiments and photoelectrochemical tests. This study provides a new idea for wastewater purification. [ABSTRACT FROM AUTHOR]

Nanocomposites of C–Ta4+ co-doped NaTaO 3 and reduced graphene oxide (C-NTO/rGO) with highly efficient photocatalytic activity were fabricated by a one-step solvothermal reaction. The optimum composites C-NTO/3rGO (with 3 wt% rGO) exhibited superior photocatalytic activity for the degradation of RhB over a mono-component counterpart under visible light irradiation. The photocatalytic efficiency was found to be as high as 97% for 90 min. Both XRD and XPS characterizations indicated that the doping of carbon into the NaTaO 3 lattice leads to the reduction of Ta5+ to Ta4+. Furthermore, the co-doping significantly narrows the band gap (about 2.8 eV). Photo-luminescence (PL), time resolved transient PL decay spectra and photo-current results confirmed that photo-induced hole-electron pairs can be effectively separated resulting from the introduction of rGO. The synergistic effect of a decreased band gap and highly effective separation of photo-generated electrons and holes may be responsible for the enhanced photocatalytic activity of the fabricated nanocomposites. Both h+ and •OH active radicals were found to be the key factors for the photo-decomposition process of RhB over the nanocomposites, while •O 2 − was also involved to a smaller extent. A possible photo-degradation mechanism for C-NTO/rGO was proposed on the basis of the experiments results. [Display omitted] • Visible light-active co-doped NaTaO 3 and reduced graphene oxide photocatalysts were fabricated. • The photocatalysts exhibited high performance for the degradation of rhodamine B. • The narrowed band gap and effective separation of electron-hole were responsible for the excellent performance. • The photo-degradation mechanism for the enhanced activity was discussed deeply. [ABSTRACT FROM AUTHOR]

In this study, rGO/Bi 2 O 2 CO 3 /BiOCl composite photocatalysts were prepared using a one-step solvothermal method. The formation and morphology of these photocatalysts were characterized through XRD, Raman, XPS, SEM, TEM, and other techniques. The efficiency of the composite photocatalysts was assessed by decreasing RhB under visible light. Among them, the photocatalytic activity of 4 wt% rGO/Bi 2 O 2 CO 3 /BiOCl was discovered to be the best, with a degradation rate as high as 96 % within 60 min. This is because the inclusion of rGO not only increased the specific surface area of the ternary materials, but also acted as a carrier for electrons transfer. Besides, the heterojunction structure constituted between Bi 2 O 2 CO 3 and BiOCl also opens up a new pathway for carrier separation. Finally, we explored the degradation mechanism of rGO/Bi 2 O 2 CO 3 /BiOCl ternary materials in detail. This study holds an important reference for the synthesis of bismuth-based composite photocatalysts and has potential applications in wastewater treatment. [Display omitted] • The rGO/Bi 2 O 2 CO 3 /BiOCl photocatalysts were synthesized using a simple one-step solvothermal method. • The ternary photocatalysts represented excellent photocatalytic activity on degrading RhB under visible light. • Here is one major reason for the increase in catalytic activity: fast multiple charge transfer paths. • The degradation mechanism utilizes three active free radicals efficiently, and the degradation effect is remarkable. [ABSTRACT FROM AUTHOR]