Abtar Mishra

Bio: Abtar Mishra is an academic researcher from National Institute of Technology, Rourkela. The author has contributed to research in topics: Intracellular & Autophagy. The author has an hindex of 7, co-authored 17 publications receiving 304 citations. Previous affiliations of Abtar Mishra include Siksha O Anusandhan University.

One pot synthesis of CdS/BiOBr/Bi2O2CO3: A novel ternary double Z-scheme heterostructure photocatalyst for efficient degradation of atrazine

Abstract: In this study, a simple one-step hydrothermal method was developed for morphology controlled synthesis of CdS/BiOBr/Bi2O2CO3 ternary heterostructure materials. The ternary system contained well dispersed CdS nanoparticles (50–80 nm) anchored over ultrathin BiOBr and Bi2O2CO3 nanoplates with high interfacial contact. A significant enhancement in visible light absorption, prolonged life time decay and improved charge carrier separation and migration property accounted for the excellent photocatalytic activity towards atrazine herbicide degradation (>95% in 30 min). A double Z-scheme electron transfer mechanism was proposed to explain the dramatic increase in photocatalytic activity which was deduced from photoelectrochemical measurements, scavenger and radical ( OH and O2 ‾) trapping experiments. MTT assay study revealed that the photo-catalytically treated atrazine solution showed significant reduction in cytotoxicity. This study provides an effective strategy for facile synthesis of bismuth based ternary heterostructures with potential applications in the field of environmental remediation.

A facile reflux method for in situ fabrication of a non-cytotoxic Bi2S3/β-Bi2O3/ZnIn2S4 ternary photocatalyst: a novel dual Z-scheme system with enhanced multifunctional photocatalytic activity

Abstract: In this study, we have developed a novel non-cytotoxic Bi2S3/β-Bi2O3/ZnIn2S4 ternary nanocomposite using a mild in situ reflux method for multimodal applications in the fields of waste water remediation, H2 energy production and microbial disinfection. Initially, the metastable β-Bi2O3 phase with nanoplate morphology was synthesized by thermal decomposition of Bi2O2CO3. The co-assembly of Bi2S3 and ZnIn2S4 with β-Bi2O3 is achieved by a tailor made in situ reflux route using thioacetamide as the sulfur source. Comprehensive characterization of the ternary composite revealed close microscopic contact between the semiconductors, fast electron channelization, enhanced charge carrier separation and a prolonged life time (11.25 ns) of the excited state. The ternary composite exhibits excellent visible light assisted photocatalytic activity for aqueous phase tetracycline (TCN) degradation and Cr(VI) reduction achieving 96.3% (Kapp = 0.0868 min−1) and 93.7% (Kapp = 0.2236 min−1) removal in a short reaction span of 40 min and 12 min, respectively. The ternary composite also afforded a H2 generation rate of 2243 μmol h−1 g−1 with an apparent conversion efficiency of 14.3%. A bacterial inactivation study conducted using Enterobacter cloacae suggested good visible light assisted bacterial degradation activity of the coupled semiconductor system. The MTT assay study confirms the non-cytotoxic nature of the photocatalyst as well as the treated TCN and Cr(VI) solutions. A synergistic dual Z-scheme electron migration mechanism is deduced from radical trapping experiments and the ESR study which accounts for the excellent photocatalytic activity of the ternary composite material.

Facile Synthesis and Application of CdS/Bi20TiO32/Bi4Ti3O12 Ternary Heterostructure: A Synergistic Multi-heterojunction Photocatalyst for Enhanced Endosulfan Degradation and Hydrogen Evolution Reaction

Abstract: Facile fabrication of visible light responsive multicomponent heterostructure photocatalysts with synergistic photoelectron migration is an effective approach with potential application in water remediation and renewable energy generation. In this study, a series of ternary multi-heterojunction CdS/Bi20TiO32/Bi4Ti3O12 (CdSxBTC) photocatalysts were prepared by hydrothermal deposition of CdS nanoparticles (15–25 nm) over one pot combustion synthesized Bi20TiO32/Bi4Ti3O12 (BTC) nanostructures. Comprehensive characterization of the ternary composites revealed enhanced optical absorption, high interfacial contact, fast electron channelization and a prolonged excited state life time. The CdSxBTC composite materials displayed enhanced photocatalytic activity for endosulfan degradation (kapp value 6–12 times greater than pure semiconductors) and water splitting reaction (H2 production rate 1890 μmolg−1h−1 and apparent conversion efficiency 19%). The cell viability -study disclosed non-cytotoxic nature of the treated endosulfan solution. A synergistic Type-I bridged coupled Z-scheme electron migration process accounted for robust radical generation ability (•O2− and •OH) and photocatalytic activity of the ternary composites.

Recent advances in graphene-based biosensor technology with applications in life sciences

Abstract: Graphene’s unique physical structure, as well as its chemical and electrical properties, make it ideal for use in sensor technologies. In the past years, novel sensing platforms have been proposed with pristine and modified graphene with nanoparticles and polymers. Several of these platforms were used to immobilize biomolecules, such as antibodies, DNA, and enzymes to create highly sensitive and selective biosensors. Strategies to attach these biomolecules onto the surface of graphene have been employed based on its chemical composition. These methods include covalent bonding, such as the coupling of the biomolecules via the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide reactions, and physisorption. In the literature, several detection methods are employed; however, the most common is electrochemical. The main reason for researchers to use this detection approach is because this method is simple, rapid and presents good sensitivity. These biosensors can be particularly useful in life sciences and medicine since in clinical practice, biosensors with high sensitivity and specificity can significantly enhance patient care, early diagnosis of diseases and pathogen detection. In this review, we will present the research conducted with antibodies, DNA molecules and, enzymes to develop biosensors that use graphene and its derivatives as scaffolds to produce effective biosensors able to detect and identify a variety of diseases, pathogens, and biomolecules linked to diseases.

In situ Irradiated XPS Investigation on S-Scheme TiO2@ZnIn2S4 Photocatalyst for Efficient Photocatalytic CO2 Reduction

Abstract: Reasonable design of efficient hierarchical photocatalysts has gained significant attention. Herein, a step-scheme (S-scheme) core-shell TiO2 @ZnIn2 S4 heterojunction is designed for photocatalytic CO2 reduction. The optimized sample exhibits much higher CO2 photoreduction conversion rates (the sum yield of CO, CH3 OH, and CH4 ) than the blank control, i.e., ZnIn2 S4 and TiO2 . The improved photocatalytic performance can be attributed to the inhibited recombination of photogenerated charge carriers induced by S-scheme heterojunction. The improvement is also attributed to the large specific surface areas and abundant active sites. Meanwhile, S-scheme photogenerated charge transfer mechanism is testified by in situ irradiated X-ray photoelectron spectroscopy, work function calculation, and electron paramagnetic resonance measurements. This work provides an effective strategy for designing highly efficient heterojunction photocatalysts for conversion of solar fuels.

Nanostructured CdS for efficient photocatalytic H 2 evolution: A review

Abstract: Cadmium sulfide (CdS)-based photocatalysts have attracted extensive attention owing to their strong visible light absorption, suitable band energy levels, and excellent electronic charge transportation properties. This review focuses on the recent progress related to the design, modification, and construction of CdS-based photocatalysts with excellent photocatalytic H2 evolution performances. First, the basic concepts and mechanisms of photocatalytic H2 evolution are briefly introduced. Thereafter, the fundamental properties, important advancements, and bottlenecks of CdS in photocatalytic H2 generation are presented in detail to provide an overview of the potential of this material. Subsequently, various modification strategies adopted for CdS-based photocatalysts to yield solar H2 are discussed, among which the effective approaches aim at generating more charge carriers, promoting efficient charge separation, boosting interfacial charge transfer, accelerating charge utilization, and suppressing charge-induced self-photocorrosion. The critical factors governing the performance of the photocatalyst and the feasibility of each modification strategy toward shaping future research directions are comprehensively discussed with examples. Finally, the prospects and challenges encountered in developing nanostructured CdS and CdS-based nanocomposites in photocatalytic H2 evolution are presented.