Synthesis of Novel Ternary Dual Z-scheme AgBr/LaNiO3/g-C3N4 Composite with Boosted Visible-Light Photodegradation of Norfloxacin

Promoting the separation of photogenerated charges and enhanced optical absorption capacity is the main means to modify photocatalytic capacities to advance semiconductor photocatalyst applications. For the first time, a novel ternary photocatalyst for dual Z-scheme system AgBr/LaNiO3/g-C3N4 (ALG) was prepared via a modest ultrasound-assisted hydrothermal method. The results indicated that LaNiO3 nanoballs and AgBr nanoparticles were successfully grown on the surface of g-C3N4 nanosheets. A dual Z-scheme photocatalytic reaction system could be constructed based on the energy band matching within AgBr, LaNiO3 and g-C3N4. Metallic Ag during the photocatalytic reaction process acted as the active electrons transfer center to enhance the photocatalytic charge pairs separation. The chemical composition of ALG was optimized and composites with 3% AgBr, 30% LaNiO3 and 100% g-C3N4 which was noted as 3-ALG displayed the best photocatalytic performance. A total of 92% of norfloxacin (NOR) was photodegraded within two hours over ALG and the photodegradation rate remained >90% after six cycles. The main active species during the degradation course were photogenerated holes, superoxide radical anion and hydroxyl radical. A possible mechanism was proposed based on the synergetic effects within AgBr, LaNiO3 and g-C3N4. This work would offer a credible theoretical basis for the application of dual Z-scheme photocatalysts in environment restoration.

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Fabrication of La2O3/g-C3N4 Heterojunction with Enhanced Photocatalytic Performance of Tetracycline Hydrochloride

Crystals ◽

10.3390/cryst11111349 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1349

Author(s):

Zhengru Zhu ◽

Haiwen Xia ◽

Rina Wu ◽

Yongqiang Cao ◽

Hong Li

Keyword(s):

Hydroxyl Radicals ◽

Degradation Rate ◽

Photocatalytic Performance ◽

Superoxide Radical ◽

Active Species ◽

Tetracycline Hydrochloride ◽

Radical Anions ◽

Photocatalytic Process ◽

Composite Photocatalysts ◽

Ultrasound Assisted

In this study, La2O3/g-C3N4 heterojunction photocatalysts doped with different dosages of La2O3 were constructed by a facile ultrasound-assisted calcination approach. The as-prepared photocatalysts were characterized by XRD, FTIR, FESEM, TEM, XPS, PL and DRS to verify the composite photocatalysts’ purity and to investigate their structural, morphological and elemental composition, and their energy band. According to the results, a type of pure rod–sheet-shaped, heterostructured nanoparticle was successfully obtained. Decorated with 10% La2O3, 2 g/L of the composite sample had a 93% degradation rate for 20 mg/L tetracycline hydrochloride within 2 h under visible light at a pH of 7. After four successive photocatalytic runs, satisfactory stability and reusability was exhibited, with 70% of the tetracycline hydrochloride being removed in the final experiment. Electrons (e−), photogenerated holes (h+), superoxide radical anions (O2−) and hydroxyl radicals (OH) were the fundamental active species during the photocatalytic process and were investigated via quenching experiments. Furthermore, possible photocatalytic mechanisms were analyzed in this work.

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Electrospinning preparation of g-C3N4/Nb2O5 nanofibers heterojunction for enhanced photocatalytic degradation of organic pollutants in water

Scientific Reports ◽

10.1038/s41598-021-02161-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lu Wang ◽

Ya Li ◽

Pingfang Han

Keyword(s):

Organic Pollutants ◽

Radical Anion ◽

Carbon Nitride ◽

Superoxide Radical ◽

Active Species ◽

Photocatalytic Process ◽

Photoluminescence Spectra ◽

Calcination Process ◽

Superoxide Radical Anion ◽

Transient Photocurrent

AbstractIn this study, graphitic carbon nitride (g-C3N4) and niobium pentoxide nanofibers (Nb2O5 NFs) heterojunction was prepared by means of a direct electrospinning approach combined with calcination process. The characterizations confirmed a well-defined morphology of the g-C3N4/Nb2O5 heterojunction in which Nb2O5 NFs were tightly attached onto g-C3N4 nanosheets. Compared to pure g-C3N4 and Nb2O5 NFs, the as-prepared g-C3N4/Nb2O5 heterojunction exhibited remarkably enhanced photocatalytic activity for degradation of rhodamine B and phenol under visible light irradiation. The enhanced catalytic activity was attributed predominantly to the synergistic effect between g-C3N4 sheets and Nb2O5 NFs, which promoted the transferring of carriers and prohibited their recombination, confirmed by the measurement of transient photocurrent responses and photoluminescence spectra. In addition, the active species trapping experiments indicated that superoxide radical anion (·O2–) and hole (h+) were the major active species contributing to the photocatalytic process. With its high efficacy and ease of preparation, g-C3N4/Nb2O5 heterojunction has great potentials for applications in treatment of organic pollutants and conversion of solar energy.

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Novel Ternary Heterogeneous Reduction Graphene Oxide (RGO)/BiOCl/TiO2 Nanocomposites for Enhanced Adsorption and Visible-Light Induced Photocatalytic Activity toward Organic Contaminants

Materials ◽

10.3390/ma13112529 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2529 ◽

Cited By ~ 1

Author(s):

Zhanxin Jing ◽

Xiangyi Dai ◽

Xueying Xian ◽

Qiongshan Zhang ◽

Huojiao Zhong ◽

...

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Organic Contaminants ◽

Photocatalytic Performance ◽

Diffuse Reflectance Spectroscopy ◽

Hydrothermal Process ◽

Reaction System ◽

Cost Effective ◽

Active Species ◽

X Ray

Herein, we describe a simple and cost-effective design for the fabrication of a novel ternary RGO/BiOCl/TiO2 nanocomposites through a simple hydrothermal process. The prepared nanocomposites were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and N2 adsorption–desorption analysis. Organic contaminants—such as methylene blue (MB), methyl orange (MO), rhodamine B (RhB) and amido black-10B (AB-10B)—were employed as the target pollutants to evaluate the adsorption capacity and photocatalytic activity of RGO/BiOCl/TiO2 nanocomposites. From experimental data, it was also found that the amount of TiO2 impressed the photocatalytic performance, and the nanocomposites with 10% of TiO2 showed the best photocatalytic activity. The improved photocatalytic performance may be mainly due to the narrow band gap, and the charge separation and migration of RGO. Moreover, good recyclability was obtained from RGO/BiOCl/TiO2 nanocomposites, and scavenger tests indicated that photogenerated holes were the main active species in the reaction system. Therefore, the prepared RGO/BiOCl/TiO2 nanocomposites have broad applications foreground in pollutants purification.

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A new core–shell Z-scheme heterojunction structured La(OH)3@In2S3 composite with superior photocatalytic performance

Applied Physics A ◽

10.1007/s00339-020-04253-3 ◽

2021 ◽

Vol 127 (2) ◽

Author(s):

Shuting Hu ◽

Junfeng He ◽

Fuming Chen ◽

Bin Liu ◽

Wangjian zhai ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Photocatalytic Performance ◽

Electrochemical Impedance ◽

Cost Effective ◽

Active Species ◽

X Ray ◽

Methylene Orange ◽

Photodegradation Rate ◽

Redox Ability

AbstractConstructing Z-scheme heterojunction photocatalyst with strong redox ability to make for enhanced photocatalytic performance and efficient charge separation is extremely attractive but still underdeveloped. Herein, a Z-scheme heterojunction structured La(OH)3@In2S3 composite (labeled by “LIS”) with photocatalytic for the methylene orange (MO) degradation under simulated light irradiation has been developed. The as-prepared LIS, together with commercial La(OH)3 and pure In2S3 fabricated with the identical processing method and starting materials as those of LIS, was characterized by X-ray diffraction, UV–vis diffuse reflectance spectra, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and electrochemical impedance spectroscopy. The results show the heterojunction of La(OH)3/In2S3 has prolonged the lifetime of the photo-generated carriers. The photocatalytic activity test shows that over only a small amount (0.02 g in 100 ml MO) of LIS, the photodegradation rate of 95% toward MO can be obtained in 90 min, which is about 3.4 times higher than that over pure In2S3. The active species trapping experiments indicate that there were four active species playing roles in photodegradation as the following order: e– = ∙OH < h+ < ∙O2–. A mechanism of Z-scheme heterojunction was proposed and well explained the enhanced photocatalytic performance. This work provides a new cost-effective photocatalyst with high photocatalytic properties.

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ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline

Catalysts ◽

10.3390/catal11080934 ◽

2021 ◽

Vol 11 (8) ◽

pp. 934

Author(s):

Yong Cheng ◽

Xiuxiu Wang ◽

Yu Mei ◽

Dan Wang ◽

Changchun Ji

Keyword(s):

Catalytic Activity ◽

Photocatalytic Degradation ◽

Photocatalytic Performance ◽

Active Species ◽

Degradation Efficiency ◽

Experimental Result ◽

Porous Nanostructure ◽

Resultant Material

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ×O2 radical was the active species in the reaction.

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The pulse radiolytic study of one-electron oxidation of hydropropidine and hydroethidine – implications for the detection of superoxide radical anion in biological systems

Free Radical Biology and Medicine ◽

10.1016/j.freeradbiomed.2018.04.517 ◽

2018 ◽

Vol 120 ◽

pp. S157 ◽

Cited By ~ 1

Author(s):

Radoslaw Michalski ◽

Bartosz Michalowski ◽

Jakub Pieta ◽

Jacek Zielonka ◽

Balaraman Kalyanaraman ◽

...

Keyword(s):

Radical Anion ◽

Superoxide Radical ◽

Biological Systems ◽

Superoxide Radical Anion

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Enhanced Photocatalytic Performance of Sn6SiO8 Nanoparticles and Their Reduced Graphene Oxide (rGO) Nanocomposite

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17814 ◽

2020 ◽

Vol 20 (9) ◽

pp. 5426-5432

Author(s):

G. Gnanamoorthy ◽

M. Muthukumaran ◽

P. Varun Prasath ◽

V. Karthikeyan ◽

V. Narayanan ◽

...

Keyword(s):

Visible Light ◽

Photocatalytic Performance ◽

Separation Efficiency ◽

Dye Degradation ◽

Hexagonal Phase ◽

Active Species ◽

Organic Chemical ◽

Light Illumination ◽

Sem Images ◽

Radical Trapping

Photocatalysts provide excellent potential for the full removal of organic chemical pollutants as an environmentally friendly technology. It has been noted that under UV-visible light irradiation, nanostructured semiconductor metal oxides photocatalysts can degrade different organic pollutants. The Sn6SiO8/rGO nanocomposite was synthesized by a hydrothermal method. The Sn6SiO8 nanoparticles hexagonal phase was confirmed by XRD and functional groups were analyzed by FT-IR spectroscopy. The bandgap of Sn6SiO8 nanoparticles (NPs) and Sn6SiO8/GO composites were found to be 2.7 eV and 2.5 eV, respectively. SEM images of samples showed that the flakes like morphology. This Sn6SiO8/rGO nanocomposite was testing for photocatalytic dye degradation of MG under visible light illumination and excellent response for the catalysts. The enhancement of photocatalytic performance was mainly attributed to the increased light absorption, charge separation efficiency and specific surface area, proved by UV-vis DRS. Further, the radical trapping experiments revealed that holes (h+) and superoxide radicals (·O−2) were the main active species for the degradation of MG, and a possible photocatalytic mechanism was discussed.

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