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Öğe A novel NH2-MIL-125/dandelion-like MnO2 nanosphere composite with a rapid interfacial electron transfer pathway for photocatalytic degradation of ornidazole(Elsevier, 2024) Patial, Shilpa; Kumar, Rohit; Sudhaik, Anita; Sonu; Thakur, Sourbh; Kumar, Naveen; Ahamad, TansirThe effectiveness of photocatalysis is constrained by the insufficient efficiency of charge separation, migration, and utilization that are generated by light. Enhanced photocatalytic efficiency is significantly achieved through the important technique of integrating Metal-Organic Frameworks (MOFs) with other materials to form heterojunction structures. In this study, NH2-MIL-125/MnO2 (NMM) composite photocatalyst has been designed, featuring a Z-scheme heterojunction structure with enhanced interfacial charge transfer and an improved lifetime of charges. The physicochemical properties of the NMM composite were analysed by multiple techniques. The photocatalytic efficiency of the NMM composite is notably superior to pristine NH2-MIL-125 and MnO2. This enhanced performance can be credited to the improvement in the recombination rate, charge transfer resistance, and adsorption site, as revealed by the characterization data. The photocatalytic performance of the NMM composite was analysed for ornidazole antibiotics degradation, which showed 91.31 % degradation efficiency at optimum conditions. In the photocatalytic degradation mechanism, center dot O-2(-) free radicals were the major oxidative species responsible for the ornidazole degradation.Öğe Advanced photo-Fenton assisted degradation of tetracycline antibiotics using ?-Fe2O3/CdS/SiO2 based S-scheme photocatalyst(Elsevier, 2024) Sharma, Kirti; Sudhaik, Anita; Sonu; Kumar, Rohit; Nguyen, Van-Huy; Le, Quyet Van; Ahamad, TansirIn the present work, we have explored the construction of ternary alpha-Fe2O3/CdS/SiO2 S-scheme nanocomposite for the removal of tetracycline (TC) antibiotic. The ternary alpha-Fe2O3/CdS/SiO2 nanocomposite was fabricated using the co-precipitation method and was characterized via various analytical and spectroscopic techniques to explore their structural properties. The alpha-Fe2O3/CdS binary magnetic nanocomposite was attached to the surface of SiO2 nanoparticles, which served as an effective support material with improved chemical stability and good visible-light absorption capabilities. Among the synthesized bare (alpha-Fe2O3, CdS, SiO2) and ternary photocatalysts, the alpha-Fe2O3/CdS/SiO2 nanocomposite exhibited the highest TC photodegradation efficiency (99 %) at pH 3 within 120 min of light illumination using 60 mg/L catalyst dose and 7 x 10(-4) M of H2O2 concentration (30 % V/V). In comparison to bare photocatalysts, the photo-Fenton assisted photocatalytic reactions of ternary heterojunction boosted charge carrier separation and mobility (confirmed from PL and EIS analysis). Additionally, it could prolong the reactive oxygen species generation which significantly improved the degradation rate of TC by ternary nanocomposite. Furthermore, the generation of superoxide (O-center dot(2)-) and hydroxyl ((OH)-O-center dot) radicals, i.e. reactive oxygen species, played an imperative role in the TC degradation process which were validated through scavenging experiments and ESR analysis. This study displayed the effectiveness of the S-scheme alpha-Fe2O3/CdS/SiO2 ternary heterostructure-based Photo-Fenton system exhibiting enhanced charge separation and migration for boosted photocatalytic efficiency. After four rounds, the photocatalytic activity demonstrated only a minor decline in catalytic efficiency.Öğe Construction of novel BiOI/CuInS2/ZnO dual S-scheme charge transfer pathway for efficient antibiotic degradation(Pergamon-Elsevier Science Ltd, 2024) Banyal, Rahul; Sudhaik, Anita; Kumar, Rohit; Raizada, Pankaj; Ahamad, Tansir; Kaya, Savas; Maslov, Mikhail M.The present work explored the photocatalytic activity of BiOI-CuInS2-ZnO ternary heterojunction for the photodegradation of the tetracycline (TCl). The bare photocatalysts were prepared via hydrothermal method while the ternary heterojunction was synthesized using simple physical mixing route. The ternary heterojunction of BiOI, CuInS2 and ZnO followed the S-scheme charge transfer pathway exhibiting superior photodegradation ability compared to other synthesized photocatalysts. The attained degradation efficiency of BiOI-CuInS2-ZnO Sscheme ternary heterojunction was 96.75 % within 90 min of light illumination which was much higher than other photocatalysts. Electron spin resonance (ESR) investigations and scavenging experiment indicated that O-center dot(2)-, and (OH)-O-center dot radicals plays an important role in photodegradation of TCl. Furthermore, the structural analysis of synthesized bare photocatalysts was also done via density functional theory (DFT) calculations. The results showed that after the formation of S-scheme heterojunction, the ternary heterojunction showed lower recombination rate (validated via PL analysis) with boosted charge carriers separation rate (confirmed through EIS and TPR analysis) and light absorption ability. This had led to upgradation in photodegradation efficiency of ternary BiOI-CuInS2-ZnO photocatalyst. The reusability test of the photocatalysts confirmed excellent stability of ternary photocatalysts with 90.25 % degradation rate up to five catalytic cycles.Öğe Dual S-scheme-based ternary BiOCl/CuInS2/WO3 heterojunction for Victoria blue photodegradation(Elsevier, 2024) Banyal, Rahul; Sudhaik, Anita; Soni, Vatika; Kumar, Rohit; Sonu, Sonu; Raizada, Pankaj; Ahamad, TansirPhotocatalysis has great potential for transforming sustainable solar energy into chemical energy, offering significant benefits for environmental applications. However, the rapid charge carrier recombination in pristine semiconductors is a big challenge. S-scheme heterojunction strategy is one of the effective strategies to overcome this challenge. The present work explored the photodegradation ability of the BiOCl-CuInS2-WO3 heterojunction against Victoria blue (VIB) dye. The pristine photocatalysts (i.e. BiOCl, CuInS2, WO3) were fabricated hydrothermally, however the BiOCl-CuInS2-WO3 ternary photocatalyst was constructed via a facile physical mixing. The BiOCl-CuInS2-WO3 ternary photocatalyst followed dual S-scheme charge migration route as per the band alignments which lead to upgraded photodegradation ability in comparison to other pristine photocatalysts. The S-Scheme heterojunction formation offered enhanced charge separation and the separated charge carriers carry out degradation process in presence of light. The photodegradation rate of BiOCl-CuInS2-WO3 dual S-scheme heterojunction was 99.24 % after 90 min, that was superior than other photocatalysts. Similarly, via ESR studies and scavenging experiments, the significant role of O-center dot(2)-, and (OH)-O-center dot radicals was determined in the degradation of VIB. Also, the S-scheme heterojunction resulted in extended light absorption ability with reduced recombination rate (verified by PL analysis) and higher separation rate of photocarriers (confirmed by EIS and TPR analysis) in ternary heterojunction. This resulted in improved photodegradation effectiveness of the ternary BiOCl-CuInS2-WO3 photocatalyst. The stability of the formed heterojunction was verified via reusability tests which displayed 90.25 % degradation efficiency after 5 successive catalytic cycles.Öğe Emergence of S-scheme-derived Ag decorated CuBi2O4/CNTs/(BiO)2CO3 photocatalyst with enhanced visible light photocatalytic performance(Elsevier, 2024) Dutta, Vishal; Sonu; Sudhaik, Anita; Kumar, Rohit; Raizada, Pankaj; Ahamad, Tansir; Alshehri, Saad M.Background: Due to advantages like low cost, and high catalytic efficiency, photocatalysis has attracted more and more attention. The present investigation presents a straightforward and cost-effective hydrothermal method for producing Ag-decorated CuBi2O4/CNTs/(BiO)(2)CO3 composites with varying weight percentages of (BiO)(2)CO3. Methods: Herein, systematic investigations were conducted to examine the crystal, morphological, and optical properties of the photocatalysts. The investigation focused on evaluating the photocatalytic performance via visible light-assisted photodegradation of methyl orange (MO) and rhodamine B (RhB). Significant findings: Findings revealed that loading of (BiO)(2)CO3 efficiently improved the photoactivity of the composite. The Ag-CuBi2O4/CNTs/(BiO)(2)CO3 heterojunction photocatalyst with 15 % loading of (BiO)(2)CO3 has expressively enhanced photocatalytic performance, estimated around 97.79 % of RhB and 98.29 % of MO photo-degraded within 70 min in visible light irradiation, which was also found much enhanced than that of bare CuBi2O4 and (BiO)(2)CO3. Re-cyclic experiments indicated that fabricated semiconductor hybrid photo-catalyst own good photo-stability as well as reusability. The involvement of center dot O-2- and center dot OH active radical species in the process of increased photo-degradation has been demonstrated using ESR and radical trapping tests. The description of the full photocatalytic mechanism based on the S-scheme was conducted by considering the estimated energy band locations, electron spin resonance (ESR) analysis and reactive oxygen species (ROS) trapping tests. This study presents a pragmatic methodology for the development of wide-bandgap bismuth-derived semiconductors that exhibit effective photo-degradation for environmental remediation.Öğe Fabrication of a dual Z-scheme Ag3PO4/g-C3N4/Bi2MoO6 ternary nanocomposite for effective degradation of methylene blue dye(Springer, 2024) Chauhan, Akanksha; Khan, Aftab Aslam Parwaz; Sudhaik, Anita; Kumar, Rohit; Katin, Konstantin P.; Kaya, Savas; Raizada, PankajMethylene blue is a recognized carcinogen with detrimental effects on both people and marine life. Henceforth, in this study, the photocatalytic activity of Ag3PO4/g-C3N4/Bi2MoO6 (AP/GCN/BMO) photocatalyst was investigated for the degradation of MB dye from an aqueous system. g-C3N4, BMO and AP photocatalysts bare photocatalysts were synthesized via thermal polycondensation, hydrothermal and co-precipitation methods, respectively. Similarly, binary (GCN/BMO) and ternary heterojunctions (AP/GCN/BMO) was constructed through in-situ hydrothermal and co-precipitation methods, respectively. Morphological and structural analysis validated close interaction amongst Ag3PO4, g-C3N4, and Bi2MoO6 photocatalysts. Furthermore, density functional theory simulations were employed to explore the structural and electronic properties of the bare (Ag3PO4, g-C3N4, and Bi2MoO6) photocatalysts. The photocatalytic degradation experiments revealed that AP/GCN/BMO exhibited highest adsorption and photocatalytic degradation efficacy of methylene blue (MB) dye pollutant as compared to other photocatalysts. The achieved MB dye degradation efficiency of dual Z-scheme AP/GCN/BMO ternary photocatalyst was approx. ~94% within 60 min under visible light exposure which was much greater than pristine and binary photocatalysts. This higher efficiency was accredited to dual Z-scheme type of charge transfer route which boosted photocarriers charge separation and transferal rate. Furthermore, through scavenging experiment, the confirmed reactive species in this type of charge transfer route were •O2? and •OH radicals that efficiently degraded MB dye pollutant. Additionally, the ternary photocatalyst demonstrated good stability and recyclability for up to five successive catalytic cycles with 81% degradation efficiency. The current work extends our understanding of photocatalytic degradation by providing novel strategies for pollutant degradation that successfully degrade contaminants. Also, it promotes the development of more efficient, environmentally friendly waste treatment methods that uses solar/light energy. Graphical Abstract: (Figure presented.) © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Öğe Photocatalysis and adsorption coupling in S-scheme K and P doped g-C3N4/GO/MgFe2O4 photocatalyst for enhanced degradation of Congo red dye(Iop Publishing Ltd, 2025) Kumar, Rohit; Khan, Aftab Aslam Parwaz; Sudhaik, Anita; Sonu, Sonu; Kaya, Savas; Singh, Pardeep; Raizada, PankajPhotocatalysis is an environmentally friendly approach for harnessing solar light to degrade pollutants. This study investigates the degradation of Congo red (COR) dye by a visible light-active photocatalyst, with a primary focus on the efficiency and reusability of the photocatalytic material. We synthesized phosphorus- and potassium-doped graphitic carbon nitride photocatalysts attached to graphene oxide and MgFe2O4 (KPCN/GO/MgFe2O4). Doping graphitic carbon nitride enhanced light absorption, while graphene oxide improved the adsorption properties. The addition of magnetic MgFe2O4 enhanced charge separation and reusability. The KPCN/GO/MgFe2O4 composite was analyzed using a range of techniques. The activity of the synthesized materials for Congo red (COR) dye degradation was analyzed under visible light. The photocatalytic activities of bare, binary, and ternary photocatalysts were compared, and KPCN/GO/MgFe2O4 exhibited the highest photoactivity among all. The KPCN/GO/MgFe2O4 photocatalyst (60 mg) showed a 76% removal efficiency for 5 x 10-6 M Congo red within 60 min, which was 2.5 times higher than that of pure graphitic carbon nitride. The OH and O2- were the major reactive species during COR photodegradation. The photocatalyst also displayed good reusability after five cycles, enhancing its overall effectiveness.Öğe Recent advances in manipulating strategies of NH2-functionalized metallic organic frameworks-based heterojunction photocatalysts for the sustainable mitigation of various pollutants(Academic Press Inc Elsevier Science, 2024) Kaur, Balvinder; Soni, Vatika; Kumar, Rohit; Singh, Pardeep; Selvasembian, Rangabhashiyam; Singh, Archana; Thakur, SourbhNH2-functionalized metal-organic frameworks (NH2-functionalized MOFs) can abate organic pollutants, predominantly favored by their chemical, mechanical, and thermal stabilities. The present review stated the chemistry of identifying NH2-functionalization and its role in enhancing the properties of bare MOFs. The integration of the amine group bestows several advantages: 1.) enabling band structure modification, 2.) establishing strong metal-NH2 bonds, 3.) preserving MOF structures from reactive oxygen species, and 4.) shielding MOF structures against pH alterations. Consequently, the NH2-functionalized MOFs are promising materials for the photodegradation of organic contaminants. The following section illustrates the two approaches (pre-synthetic and post-synthetic) for NH2-functionalized MOFs. Nevertheless, specific intrinsic limitations, entailing a high recombination rate of charge carriers and inadequate optical adsorption, restrain the applicability of NH2-functionalized MOFs. Accordingly, the succeeding segment presents strategies to elevate the photocatalytic activities of NH2-functionalized MOFs via heterojunction fabrication. The importance of the NH2- functionalized MOFs-based heterojunction has been evaluated in terms of the effect on the enhancement of charge separation, optical adsorption, and redox ability of charge carriers. Subsequently, the potential application for organic pollutant degradation via NH2-functionalized MOFs-based heterojunctions has been scrutinized, wherein the organic pollutants. Eventually, the review concluded with challenges and potential opportunities in engaging and burgeoning domains of the NH2-functionalized MOFs-based heterojunctions.Öğe Tailoring dual S-Scheme based g-C3N4/ZnO/TiO2 ternary photocatalytic system immobilized on floating cork for environmental remediation(Elsevier, 2025) Rana, Anchal; Sonu, Sonu; Sudhaik, Anita; Kumar, Rohit; Chawla, Akshay; Raizada, Pankaj; Chaudhary, VishalBackground: Light harvesting and reusability are the key factors for highly effective solar photocatalysis. Floating photocatalysts can maximize light utilization and be recycled easily, making them a strong candidate for real-world environmental applications. Methods: In this article, a novel dual s-scheme-based g-C3N4/ZnO/TiO2/Cork photocatalyst was constructed via a co-precipitation process followed by physical blending of the floating materials. In g-C3N4/ZnO/TiO2/Cork photocatalyst, cork acted as a floating substrate to enhance light exposure, oxygen availability, and reusability. The dual S-scheme charge transfers between g-C3N4, ZnO, and TiO2 improves carriers' charge separation and concentration. Advanced Spectral techniques were utilized to compare and analyze the morphological, structural, and optical characteristics. The photocatalytic activity was further analyzed by using methyl orange (MO) and doxycycline hydrochloride (DCl) as target pollutants. Significant findings: The g-C3N4/ZnO/TiO2/Cork heterojunction exhibited excellent photodegradation activity against MO dye (98.25 %) and DCl antibiotic (79.27 %) within 60 min under visible light. The scavenger experiment revealed that the O-center dot(2)- and (OH)-O-center dot radicals were the major reactive species in this photocatalytic experiment. Additionally, a better recyclability was also demonstrated by the g-C3N4/ZnO/TiO2/Cork heterojunction photocatalyst.
