Enhanced visible light photocatalytic activity and stability of CQDs/BiOBr composites: The upconversion effect of CQDs

Duo, Fangfang; Wang, Yawen; Fan, Caimei; Zhang, Xiaochao; Wang, Yunfang

doi:10.1016/j.jallcom.2016.05.259

Cited by 100 publications

(23 citation statements)

References 50 publications

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“…16,17 However, the pure BiOBr photocatalyst still faces some challenges which seriously limit its photocatalytic activity; thus, the further optimization of the conventional BiOBr photocatalyst is quite desirable and urgent. [18][19][20] To our knowledge, the photocatalysis reaction process mainly contains three parts. [21][22][23] The rst part is solar energy harvesting, in which the semiconductor photocatalysts absorb solar energy and generate electrons and holes.…”

Section: -13mentioning

confidence: 99%

Efficient photocatalytic dye degradation over Er-doped BiOBr hollow microspheres wrapped with graphene nanosheets: enhanced solar energy harvesting and charge separation

et al. 2017

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In this work, Er-doped BiOBr hollow microspheres wrapped with graphene nanosheets, which acted as a photocatalyst with excellent photocatalytic activity and stability, have been successfully synthesized through a simple two-step hydrothermal method. The related properties of the as-prepared photocatalyst were analyzed and a possible reaction mechanism was proposed. Incorporating the rareearth element Er into the BiOBr crystal lattice can greatly expand the optical window, maybe owing to the reduced energy band gap by the impurity energy level introduced below the conduction band and indirect utilization of long-wavelength visible light caused by the up-conversion performance. The wrapping with surface graphene nanosheets can efficiently promote charge separation and transmission over the hybrid photocatalyst. The synergistic effect between efficient solar energy harvesting and charge separation gives rise to a remarkable improvement of photocatalytic activity for RhB degradation under simulated sunlight irradiation. In addition, the as-prepared photocatalyst possesses excellent photocatalytic stability, mainly due to the robust coordination interaction between the graphene and the (001) facets of the BiOBr subunits. The rational design of this highly active and stable photocatalyst provides a promising approach for future applications.

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Section: -13mentioning

confidence: 99%

Efficient photocatalytic dye degradation over Er-doped BiOBr hollow microspheres wrapped with graphene nanosheets: enhanced solar energy harvesting and charge separation

et al. 2017

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“…Considering the loss of catalyst in each cycling process and the test error, the experimental results imply that the CQDs/Bi 2 O 2 CO 3 possessed good stability. This suggests that the oxygen vacancies of CQDs/Bi 2 O 2 CO 3 could effectively be refreshed by the up-conversion effect of CQDs, and therefore, CQDs/Bi 2 O 2 CO 3 possess good stability [55]. CQDs/Bi 2 O 2 CO 3 materials have great potential and prospects for practical application in the future.…”

Section: Resultsmentioning

confidence: 99%

“…The photocurrent intensity of CQDs/Bi 2 O 2 CO 3 was higher than that of Bi 2 O 2 CO 3 (0.11 mA/cm 2 ). The results demonstrated that CQDs in CQDs/Bi 2 O 2 CO 3 effectively improved the separation of the photogenesis charge, and increased the numbers of generated electrons [55], thus improving the degradation efficiency. These results were consistent with PL analysis (Figure 3); the electrochemical impedance spectra (EIS) (Figure 10) further confirmed this fact.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Photocatalytic Activity toward Organic Pollutants Degradation and Mechanism Insight of Novel CQDs/Bi2O2CO3 Composite

Zhang

Lin

et al. 2018

Nanomaterials

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Novel carbon quantum dots (CQDs) modified with Bi2O2CO3 (CQDs/Bi2O2CO3) were prepared using a simple dynamic-adsorption precipitation method. X-ray diffractometry (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM) were used to test the material composition, structure, and band structures of the as-prepared samples. Methylene blue (MB) and colorless phenol, as target organic pollutants, were used to evaluate the photocatalytic performance of the CQDs/Bi2O2CO3 hybrid materials under visible light irradiation. Experimental investigation shows that 2–5 nm CQDs were uniformly decorated on the surface of Bi2O2CO3; CQDs/Bi2O2CO3 possess an efficient photocatalytic performance, and the organic matter removal rate of methylene blue and phenol can reach up to 94.45% and 61.46% respectively, within 2 h. In addition, the degradation analysis of phenol by high performance liquid chromatography (HPLC) proved that there are no other impurities in the degradation process. Photoelectrochemical testing proved that the introduction of CQDs (electron acceptor) effectively suppresses the recombination of e−-h+, and promotes charge transfer. Quenching experiments and electron spin resonance (ESR) suggested that ·OH, h+, and ·O2− were involved in the photocatalytic degradation process. These results suggested that the up-conversion function of CQDs could improve the electron transfer and light absorption ability of photocatalysts and ·O2− formation. Furthermore, the up-conversion function of CQDs would help maintain photocatalytic stability. Finally, the photocatalytic degradation mechanism was proposed according to the above experimental result.

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“…18,19 Very recently, a series of CQDs-based photocatalysts have been synthesized and the enhanced activity was obtained, such as CQDs/Cu 2 O, 20 CQDs/TiO 2 , 8 CQDs/Bi 2 WO 6 , 16 CQDs/Fe 2 O 3 , 21 CQDs/Bi 2 MoO 6 , 22 CQDs/Fe 3 O 4 , 23 CQDs/BiOCl, 24 CQDs/BiOBr. 4,5,25 Herein, considering the superiorities of BiOX/BiOY and CQDs mentioned before, we report the fabrication of a novel BiOBr/BiOCl/CQDs nanocomposite photocatalyst via a facile method for the rst time. The structure-activity relationships were studied in details.…”

Section: Introductionmentioning

confidence: 98%

BiOBr/BiOCl/carbon quantum dot microspheres with superior visible light-driven photocatalysis

Zhao

Liang

et al. 2017

RSC Adv.

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Enhanced visible light photocatalytic activity and stability of CQDs/BiOBr composites: The upconversion effect of CQDs

Cited by 100 publications

References 50 publications

Efficient photocatalytic dye degradation over Er-doped BiOBr hollow microspheres wrapped with graphene nanosheets: enhanced solar energy harvesting and charge separation

Efficient photocatalytic dye degradation over Er-doped BiOBr hollow microspheres wrapped with graphene nanosheets: enhanced solar energy harvesting and charge separation

Enhanced Photocatalytic Activity toward Organic Pollutants Degradation and Mechanism Insight of Novel CQDs/Bi2O2CO3 Composite

BiOBr/BiOCl/carbon quantum dot microspheres with superior visible light-driven photocatalysis

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