Semiconductor Nanocomposites Research Articles

Utilization of copper chromite-reduced graphene oxide nanocomposite for the wastewater remediation and effective supercapacitive performance

This article has detailed the growth of virgin copper chromite nanoparticles (CuCr2O4 NPs) and reduced graphene oxide sheet (rGO)-based CuCr2O4 nanocomposite through the process of reflux condensation method and calcination process. When exposed to visible light, these two synthesized nanomaterials exhibit enhanced photocatalytic activity which helps in the degradation of organic dyes such as methylene blue. Numerous characterization methods, including FTIR, UV–visible analysis, and XRD, verify the creation of these nanomaterials. The CuCr2O4-rGO nanocomposite's semiconductor nature is confirmed by the band gap analysis using Tauc's formula. The CuCr2O4 NPs grown on the rGO surface have a dimension of 6 nm, according to the TEM study and particle distribution graph. To find the reason for the enhanced photo-activity, we have proposed a photocatalytic mechanism which is supported by photoluminescence result. Recyclability in five more cycles is used to measure the stability of the nanocomposite, and it is found that photocatalytic efficiency does not significantly decline up to five cycles. When exploring the CuCr2O4-rGO nanocomposite as a material for supercapacitor electrodes, it showcased a remarkable specific capacity of 681.43 F/g at 0.5 A g−1. Moreover, the CuCr2O4-rGO nanocomposite electrode displayed a long-term life cycle, retaining 93.8 % of its initial capacity after 1200 cycles, paired with a commendable Coulombic efficiency of 95.31 % and outstanding power and energy density of 1504 W/kg and 23.66 Wh/kg respectively.

Photolysis and photocatalysis of methylene blue by graphene oxide nanoparticle under sunlight irradiation

The Hummer technique was utilised to produce graphene oxide (GO), for this research. X-ray diffraction (XRD), energy dispersive X-ray (EDX), and a field emission scanning electron microscope (FESEM) were used to examine the structural properties of GO nanoparticles.By boosting adsorption, expanding the light absorption range, and blocking electron-hole pair recombination, GO enhances the photocatalytic efficiency. The GO have enormous potential uses in the degradation of organic contaminants from wastewater, and their manufacturing is expected to be scalable using this simple process. The improved catalytic activity of GO nanoparticle has been linked to the greater adsorption susceptibility of dye molecules, high charge separation, and suppressed recombination of photogenerated electron-hole pairs brought about by the presence of GO. These results demonstrated the promising prospects for future use of graphene-based semiconductor nanocomposites as visible-light photocatalysts in the field of water purification.

An electrocatalytic sensing of 2, 6-dichlorophenol based on Dy2O3-Co3O4@CeO2 nanocomposite modified GCE: An enhanced environmental safety

Anthropogenic activities are continuously polluted our environment by releasing various kind of toxic chemicals as waste product. Their removal has gained the impressive importance among the scientists in order to maintain the integrity of our ecosystem. In this present work, Dy2O3-Co3O4@CeO2 nanocomposite (NC) was prepared by simple solution method with the aspiration to detect as well as electro-hydrolyzed the toxic chemicals in an aqueous system. Structural, morphological and optical properties of our newly synthesised nanocomposite were investigated by using advanced analytical tools such as ultraviolet–visible difused reflectance spectroscopy (UV-DRS), fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), field emission scanning electron microscope equipped with energy dispersive spectroscopy (FESEM-EDS), and transmission electron microscope (TEM) in addition to Brunauer-Emmet-Teller (BET) analysis. After detailed characterization of newly synthesized Dy2O3-Co3O4@Ce2O3 nanocomposite, it was used with 5 % PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrenesulfonate), a conducting polymer binder, to modify the glassy carbon electrode (GCE) as selective electrochemical sensor (Dy2O3-Co3O4@CeO2-NC/PEDOT:PSS/GCE). After that, this newly designed Dy2O3-Co3O4@CeO2-NC/PEDOT:PSS/GCE was evaluated so as to check its detection as well as electrocatalytic behaviour against the toxic chemicals in an aqueous system using novel electrochemical current–potential (I–V) approach, for the first time. A comparative investigation revealed that this newly designed Dy2O3-Co3O4@CeO2-NC/PEDOT:PSS/GCE was very selective against the 2, 6-dichlorophenol (2, 6-DCP) and had good affinity with it even in the company of other interference chemicals. In order to optimise newly developed Dy2O3-Co3O4@CeO2-NC/PEDOT:PSS/GCE as an effective as well as selective 2, 6-DCP electrochemical sensor, analytical parameters such as, limit of detection (LOD), limit of quantification (LOQ), sensitivity etc were calculated from slop of calibration curve. The LOD at signal-to-noise ratio (S/N) of 3, LOQ, and sensitivity were calculated as 0.014 ± 0.001 nM, 0.046 ± 0.001 nM, and 65.82 µAµM-1cm−2, respectively, over a linear dynamic range (LDR) of our target analyte concentration (0.1 nM – 0.1 M) with r2 square value as 0.9988. Consequently, this study enlightens us that this newly fabricated electrochemical sensor, selective only for 2, 6-DCP, is very cost-effective, efficient, and stable over time. Moreover, it also initiates a new way to effectively interrogate the various toxic chemicals in real samples by using a novel electrochemical (I–V) approach based on reported / non-reported different kind of semiconductor nanocomposite modified GCEs as selective electrochemical sensors.

Novel silver vanadate coupled semiconductor nanocomposites for effective removal of toxic organics

One of the world's most important challenges is the lack of access to clean water, and researchers are working tirelessly to find a solution. Nanotechnology-treated water is superior to conventionally treated water since it contains no hazardous microorganisms or organic dyes. In this study, the influence of light on Ag3VO4 nanocomposites doped with synthesized ZnO nanoparticles was analyzed. SEM, FTIR, XRD, XPS, and UV–vis spectroscopy were just some of the methods used to characterize the as-prepared nanocomposites. An Ag3VO4/ZnO nanocomposite was used to successfully adsorb and photodegrade Acid Green-16(AG-16), and Acid Red-72(AR-72) from an aqueous solution. Visible light dramatically accelerates the adsorption and photodegradation of the Ag3VO4/ZnO nanocomposite compared to complete darkness. 77.52 %, 82.86 %, and 89.56 % of AG-16 and 77.11 %, 82.74 %, and 87.91 % of AR-72 were removed by the ZnO, Ag3VO4, and Ag3VO4/ZnO nanocomposites, respectively, in less than 60 min. However, visible-light photodegradation is more successful than adsorption alone in removing AG-16 and AR-72. In this pioneering study, we assess the catalytic performance of newly synthesized ZnO incorporated Ag3VO4 nanocomposites for the UV-assisted degradation of organic dyes. Our study presents an innovative catalyst system that exhibits improved efficiency and holds promise for implementation in environmentally sustainable wastewater treatment methods.

Schinus molle extract mediated green synthesis of iron niobate photocatalyst for the degradation of methyl orange dye under visible light

FeNbO4 monoclinic nanocomposite semiconductors were synthesised using hydrothermal and sol gel methods; photocatalysts were then calcined at 800 °C. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy (UV/Vis) and X-ray diffraction (XRD) technologies were used to investigate crystallinity, morphology and optical properties of the photocatalysts. Fourier transform infrared spectroscopy (FTIR) was used to determine the functional groups of both treated and untreated FeNbO4. It was found that the S. molle extract-treated FeNbO4 prepared using the hydrothermal method (FeNbO4-HT + S. molle) has the smallest nanoparticles (22.8 nm) with the smallest band gap energy (2.78 eV). X-ray photoelectron spectroscopy verified the presence of the elements of FeNbO4 as well as their oxidation states. The photodegradation reactions of 10-ppm methyl orange dye solutions using FeNbO4-sol gel, FeNbO4-HT and FeNbO4-HT + S. molle were carried out under visible light (>420 nm) for 50 min. The reactions resulted in degradation percent of 74 %, 78 % and 96 % by using FeNbO4-sol gel, FeNbO4-HT and FeNbO4-HT + S. molle respectively. The photocatalytic activity of FeNbO4 treated with S. molle extract demonstrated superior light absorption and photostability, which is attributed to the consistency in the photocatalysts’ morphology, optical band gap, particle size distribution, and porosity. The photocatalysts remained stable and effective for five degradation cycles.

Sunlight-mediated efficient remediation of organic pollutants from water by chitosan co-decorated nanocomposites of NiO loaded with WO3: Green synthesis, kinetics, and photoactivity

Azo dyes such as Tropaeolin OOO (TOOO) and Eriochrome black T (EBT) are used in various industrial and laboratory applications. However, their recalcitrant properties make them toxic chemicals and require efficient removal-strategy based on polymer decorated semiconductor nanocomposite. Herein, photodegradation of TOOO and EBT in water was investigated at different reaction parameters through NiO@WO3-chitosan synthesized by green procedure using A. indica. PXRD spectra peaks show semi-crystalline behaviour with spherical morphology and chitosan around metal oxide. In FT-IR, New spectral peaks observed at 1023 cm−1, 870 cm−1, and 540 cm−1 vibration indicated between Ni-O-W, Ni-N, and W-N confirmed effecting coupling. Both dyes (10 mg/L) were found completely colourless within 3 h under sunlight with pH of 7 at 20 mg of catalyst load. Difference in max degradation of 96 % and 92 %, respectively to TOOO and EBT dye credit to structure difference. 1st-order reaction kinetics following early Langmuir adsorption and degradation at optimum condition rate constant k (0.26–0.19-min−1) and half time t1/2(2.68––3.64 min−1). Efficiency of NiO@WO3-chitosan was maintained due to its fine morphology with elevated surface-area (75 m2g−1), large negative zeta potential (−29.5 mV), and lesser value of band distance (2.1 eV). Involvement of •OH, O2–• and holes in photocatalysis mechanism to break complex molecules of TOOO and EBT was revealed in Scavenger analysis. After degradation, small-safer metabolites were confirmed by LC-MS. Reusability up to 8th cycle of NiO@WO3-chitosan without photoactivity reduction makes it a cost-effective cum sustainable composite for industries and wastewater pollutants removal with good surface properties.

Construction of semiconductor nanocomposites for room-temperature gas sensors.

Gas sensors are essential for ensuring public safety and improving quality of life. Room-temperature gas sensors are notable for their potential economic benefits and low energy consumption, and their expected integration with wearable electronics, making them a focal point of contemporary research. Advances in nanomaterials and low-dimensional semiconductors have significantly contributed to the enhancement of room-temperature gas sensors. These advancements have focused on improving sensitivity, selectivity, and response/recovery times, with nanocomposites offering distinct advantages. The discussion here focuses on the use of semiconductor nanocomposites for gas sensing at room temperature, and provides a review of the latest synthesis techniques for these materials. This involves the precise adjustment of chemical compositions, microstructures, and morphologies. In addition, the design principles and potential functional mechanisms are examined. This is crucial for deepening the understanding and enhancing the operational capabilities of sensors. We also highlight the challenges faced in scaling up the production of nanocomposite materials. Looking ahead, semiconductor nanocomposites are expected to drive innovation in gas sensor technology due to their carefully crafted design and construction, paving the way for their extensive use in various sectors.

Bi2O3/ZnO heterostructured semiconductor nanocomposites: synthesis, characterization and its visible light-induced degradation of methylene blue dye

Abstract In this study, we describe the creation of linked semiconductor nanomaterials, which represents a significant development for photocatalytic applications. A Bi2O3–ZnO hetrostructured thin film was created using the SILAR-CBD deposition technique. In comparison to pure ZnO and Bi2O3, the produced heterostructured thin film showed greater photocatalytic (PCD) activity for the degradation of methylene blue (MB) dye under UV light. The formation of Bi2O3 (monoclinic lattice phase) and ZnO (hexagonal wurtzite phase) are the heterostructured nanomaterials that were generated, according to a powder XRD inspection. An image taken with HR-TEM demonstrates the mixing of nanoparticles and nanorod formations in the Bi2O3/ZnO. The vectorial movement of electrons (e−) and holes (h+) between ZnO and Bi2O3 is responsible for the boosted photocatalytic efficiency, which is in turn, accountable for the enhanced photocatalytic activities.

Design and fabrication of g-C3N4/Bi2S3 heterojunction photocatalysts for efficient organic pollutant degradation and antibacterial activity

Developing highly effective photocatalysts is essential in environmental remediation and sustainable manufacturing. In this study, a carbon-based semiconductor nanocomposite (g-C3N4/Bi2S3) was effectively prepared via a hydrothermal approach. Comprehensive physicochemical characterizations were active to assess the morphological, structural, and photochemical attributes of the fabricated g-C3N4/Bi2S3 nanocomposites using microscopic and spectrophotometric analyses while the intermediate products formation was assessed through GC-MS analysis. Photocatalytic degradation performance was evaluated against Reactive Black 5 (RB5) and Indigo Carmine (IC) dyes. The g-C3N4/Bi2S3 nanocomposites exhibited remarkable photodegradation efficiency compared with pure g-C3N4 and Bi2S3 catalysts, achieving 95.6 % degradation for IC and 97.5 % for RB5 after 120 min of Ultraviolet A irradiation (UVA). This excellent photocatalytic activity demonstrates the potential of g-C3N4/Bi2S3 nanocomposites for future employment in visible-light-driven wastewater treatment. The mechanism of g-C3N4/Bi2S3 NCs photocatalysis involves efficient charge separation, active site interactions, electron and hole transfer, and subsequent oxidative removal of organic pollutants, revealing the NCs suitability for sustainable environmental applications. Furthermore, the effectiveness of the g-C3N4/Bi2S3 nanocomposites in combating Streptococcus mutans and Enterococcus faecalis was appraised under UVA light exposure to determine their antibacterial properties.

Study on Optical of Chitosan-Aminopropyltriethoxysilane-SiO2 Nanocomposite Decorated with Carbon Nanotubes

In our study, we examined the growth of SiO2-aminopropyltriethoxysilane nanoparticles decorated with carbon nanotubes (CNTs) on a chitosan matrix. This matrix was synthesized through a sol-gel process, where chitosan was dissolved into a silicate sol and subsequently gelled at 50 °C. To explore the structure, morphology, and optical properties of these semiconductor nanocomposites, we employed various analytical techniques including X-ray diffraction (XRD), transmission electron microscopy (SEM), Fourier Transform Infrared (FT-IR) spectroscopy, and UV-vis spectroscopy. From the UV-Vis spectroscopy measurements, the absorption, band gap, refractive index, and optical conductivity were extracted and analyzed with respect to the incident wavelength and content of CNTs. The incorporation of CNTs into the chitosan-SiO2-aminopropyltriethoxysilane semiconductor nanocomposite results in enhanced crystallinity, increased surface area, and modified optical properties. Therefore, it can be inferred that the optical characteristics of the chitosan-SiO2-aminopropyltriethoxysilane composite are significantly influenced by the ratio of CNT decoration.

Plasmon-assisted photocatalysis of organic pollutants by Au/Ag–TiO2 nanocomposites: a comparative study

The treatment of organic pollutants contaminated by wastewater from textile industries is a serious concern around the globe, and several techniques are being employed for its treatment. Among these, the semiconductor nanocomposite (NC)-assisted photodegradation of organic dyes has recently attracted attention. Herein, we report surface plasmon resonance (SPR) enhanced photocatalytic activities of heterogeneous photocatalysts (Au/Ag–TiO2) for wastewater treatment. To synthesize the Au/Ag–TiO2 NCs, TiO2 nanoflakes (NFs) are decorated with spherical-shaped plasmonic Au and Ag nanoparticles (NPs) of average sizes ∼13 and ∼30 nm, respectively, using a simple and cost-effective sol-gel method. In comparison to the pristine TiO2 nanoflakes and Ag–TiO2 NCs, highly stable Au–TiO2 NCs exhibit enhanced photocatalytic activity for the degradation of dye mixture (organic pollutants) under the sunlight. The optical and structural properties have been studied to find the reason behind the enhanced photocatalytic activities in Au–TiO2 NCs. The more degradation efficiency and rate constant in Au–TiO2 NCs are mainly attributed to the broad range absorption of visible light and the effective charge transfer, monitored using photoluminescence and ultrafast transient absorption spectroscopy. The total removal efficiency of organic dyes is 90.62% and the rate constant is 0.043 min−1 in 60 min degradation for Au–TiO2, higher than that of Ag–TiO2 and TiO2. Furthermore, the Stern-Volmer constant (Ksv) estimated from the photoluminescence quenching measurements is found to be significantly higher in the case of Au–TiO2 (2420 L−1) than Ag–TiO2 (1750 L−1), which corroborates the fact that there is more charge transfer in Au–TiO2. We believe that this research may shed light on the physics underlying the enhanced photocatalytic performance and capabilities of Au–TiO2 NCs for the removal of organic pollutants in wastewater.

Photocatalytic Degradation, Anticancer, and Antibacterial Studies of Lysinibacillus sphaericus Biosynthesized Hybrid Metal/Semiconductor Nanocomposites.

The biological synthesis of nanocomposites has become cost-effective and environmentally friendly and can achieve sustainability with high efficiency. Recently, the biological synthesis of semiconductor and metal-doped semiconductor nanocomposites with enhanced photocatalytic degradation efficiency, anticancer, and antibacterial properties has attracted considerable attention. To this end, for the first time, we biosynthesized zinc oxide (ZnO) and silver/ZnO nanocomposites (Ag/ZnO NCs) as semiconductor and metal-doped semiconductor nanocomposites, respectively, using the cell-free filtrate (CFF) of the bacterium Lysinibacillus sphaericus. The biosynthesized ZnO and Ag/ZnO NCs were characterized by various techniques, such as ultraviolet-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The photocatalytic degradation potential of these semiconductor NPs and metal-semiconductor NCs was evaluated against thiazine dye, methylene blue (MB) degradation, under simulated solar irradiation. Ag/ZnO showed 90.4 ± 0.46% photocatalytic degradation of MB, compared to 38.18 ± 0.15% by ZnO in 120 min. The cytotoxicity of ZnO and Ag/ZnO on human cervical HeLa cancer cells was determined using an MTT assay. Both nanomaterials exhibited cytotoxicity in a concentration- and time-dependent manner on HeLa cells. The antibacterial activity was also determined against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus). Compared to ZnO, Ag/ZnO NCs showed higher antibacterial activity. Hence, the biosynthesis of semiconductor nanoparticles could be a promising strategy for developing hybrid metal/semiconductor nanomaterials for different biomedical and environmental applications.

Facile One‐Pot Synthesis of Uniquely Designed Au−Cu2O Nanocomposites for Effective Catalytic Degradation of Azo Dyes

AbstractIn the study of metal–semiconductor nanocomposites, the Au−Cu2O system is of significant interest because it can give rise to a variety of hybrid designs with pronounced activity for catalytic applications. In this work, a facile one‐pot synthetic strategy was developed to prepare Au−Cu2O nanocomposites with a unique core–shell nanoflower configuration, where a cluster of tiny Au nanoparticles constitutes the core, while larger cube‐like Cu2O nanoparticles surround this core in a petal‐like arrangement. Unlike previously published procedures that rely on two‐pot synthesis routes to generate the Au−Cu2O hybrid, the one‐pot synthesis protocol presented in this work is a more straightforward and less laborious approach that does not require a separate pre‐synthesis step. Furthermore, the synthesis can be conveniently performed at ambient conditions using nontoxic reagents. When tested as catalysts, the uniquely designed Au@Cu2O nanoflowers were found to effectively catalyze the borohydride‐mediated degradation of synthetic azo dyes (methyl orange and congo red). The hybrid exhibited superior catalytic activity relative to pristine Cu2O, underscoring the significance of creating a nanocomposite.

Synthesis and characterization of a new semiconductor nanocomposite based on polyaniline and graphene and investigating its electrochemical and electroconductivity properties

The purpose of this study is to investigate the magnetic and electrochemical properties of the new GO/Pani-CeO2/CoFe2O4 nanocomposite. This nanocomposite was synthesized through two routes and the results of the investigations show interesting cases. The interaction between CeO2-Pani and the presence of Ce-O was confirmed by FTIR spectroscopy and the XRD data showed the successful formation of the magnetite nanoparticles with the presence of CeO2 anchored onto polyaniline within the GO matrix. X-ray photoelectron spectroscopy (XPS) showed well the presence of Ce+3 (in addition to Ce+4) and its percentage. The products were identified by other methods such as VSM, FE-SEM, and EDX. Electrochemical studies such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS) to evaluate the effect of changes in the accumulation type of the synthesized nanocomposite were recorded in 0.5 M H3PO4 vs. Ag/AgCl. The stability test also shows that the desired compound has relatively good stability as a supercapacitor.

Synthesis and characterization of rGO wrapped 1-D NiO nanofibers for ammonia gas sensing application

The fabrication of reduced graphene oxide (rGO) based metal oxide semiconductor (MOS) nanocomposites for applications at room temperature gas sensing have attracted growing interest in during recent years. The present work, one dimensional (1-D) rGO-NiO nano fibers were fabricated by employing electrospinning technique for detection of NH3 gas at room temperature. SEM, XRD, BET, DRS and XPS were used to analyse the surface morphology, structure, composition of materials and optical properties of rGO-NiO nanofibers. Ammonia gas is detected by the rGO-NiO sensor with an excellent response time of 32 s. and recovery time of 38 s. respectively for a concentration of 50 ppm at room temperature. The intrinsic charge transfer due to the synergistic effect of the heterostructure will enhance the sensing performance.

Weak interaction engineering on thermal transport in metal-organic semiconductor nanocomposites with self-assembled monolayers

The engineering of weak interactions between metals and organic semiconductors is crucial in regulating energy carrier transport within organic semiconductor electronics. In this study, we introduce self-assembled monolayers (SAMs) to improve thermal transport in metal-organic semiconductor nanocomposites. SAM molecules with different terminal groups (-CH3, -COOH, and -C6H5) and chain lengths are utilized to modify the surface of Au nanoparticles with multiple core diameters. The introduction of SAMs significantly boosts the thermal transport of metal-organic semiconductor nanocomposites, which can be attributed to improved vibrational coupling and stronger nonbonding interactions. Furthermore, longer SAM chains broaden the area of van der Waals regions and further strengthen the intermolecular interaction across the interface, reducing the interfacial thermal transport barrier. Additionally, quantum chemistry calculation and evaluations of interfacial adhesion energy indicate that the π-π stacking interaction between TPD and SAM(-C6H5) molecules forms the best interfacial combination of nanoparticles and TPD molecules, resulting the greatest thermal transport characteristics. Finally, free energy calculations demonstrate that the variation of nanoparticle surface topology with the increase of the SAM chain length induces more obvious free energy fluctuation, which leads to tighter connections between TPD and SAM molecules under weak interaction.

Effect of Nanoparticle Interaction on Structural, Conducting and Sensing Properties of Mixed Metal Oxides

This review analyzes the studies published, mainly in the last 10–15 years, on the synthesis, structure, and sensor properties of semiconductor nanocomposites. Particular attention is paid to the interaction between nanoparticles of the sensitive layer, and its effect on the structure, sensitivity, and selectivity of semiconductor sensor systems. Various mechanisms of interaction between nanoparticles in metal oxide composites are considered, including the incorporation of metal ions of one component into the structure of another, heterocontacts between different nanoparticles, and core–shell systems, as well as their influence on the characteristics of gas sensors. The experimental data and studies on the modeling of charge distribution in semiconductor nanoparticles, which determine the conductivity and sensor effect in one- and two-component systems, are also discussed. It is shown that the model which considers the interactions of nanoparticles best describes the experimental results. Some mechanisms of detection selectivity are considered in the conclusion.

A Comprehensive Study of Electrocatalytic Degradation of M-Tolylhydrazine with Binary Metal Oxide (Er2O3@NiO) Nanocomposite Modified Glassy Carbon Electrode

Generally, our ecosystem is continuously contaminated as a result of anthropogenic activities that form the basis of our comfort in our routine life. Thus, most scientists are engaged in the development of new technologies that can be used in environmental remediation. Herein, highly calcined binary metal oxide (Er2O3@NiO) semiconductor nanocomposite (NC) was synthesized using a classical wet chemical process with the intention to both detect and degrade the toxic chemicals in an aqueous medium using a novel electrochemical current–potential (I–V) approach for the first time. Optical, morphological, and structural properties of the newly synthesized semiconductor NC were also studied in detail using FT-IR, UV/Vis., FESEM-EDS, XPS, BET, EIS, and XRD techniques. Then, a modified glassy carbon electrode (GCE) based on the newly synthesized semiconductor nanocomposite (Er2O3@NiO-NC/Nafion/GCE) as a selective electrochemical sensor was fabricated with the help of 5% ethanolic-Nafion as the conducting polymer binder in order to both detect and electro-hydrolyze toxic chemicals in an aqueous medium. Comparative study showed that this newly developed Er2O3@NiO-NC/Nafion/GCE was found to be very selective against m-tolyl hydrazine (m-Tolyl HDZN) and to have good affinity in the presence of other interfering toxic chemicals. Analytical parameters were also studied in this approach to optimize the newly designed Er2O3@NiO-NC/Nafion/GCE as an efficient and selective m-Tolyl HDZN sensor. Its limit of detection (LOD) at an SNR of 3 was calculated as 0.066 pM over the linear dynamic range (LDR) of our target analyte concentration (0.1 pM–0.1 mM). The limit of quantification (LOQ) and sensitivity were also calculated as 0.22 pM and 14.50 µAµM−1cm−2, respectively. m-Tolyl HDZN is among the toxic chemicals in our ecosystem that have lethal effects in living beings. Therefore, this newly designed electrochemical sensor based on semiconductor nanostructure material offers, for the first time, a cost-effective technique, in addition to long-term stability, that can be used as an alternative for efficiently probing other toxic chemicals in real samples.

Room-Temperature Synthesis of Carbon Dot/TiO2 Composites with High Photocatalytic Activity

Benefiting from the wide-range absorption and adjustable energy gap, carbon dots (C-dots) have attracted a great deal of attention and they have been used to sensitize semiconductor nanocomposites to boost the efficiency of energy conversion devices, while there is still a lack of fundamental understanding of the interaction between such materials and their influence on the catalytic activity on the reaction process. In this study, C-dots were used to modify TiO2 to form a direct Z-scheme (DZS) junction for enhancement of the photocatalytic activity. The C-dot/TiO2 composite was prepared by ultrasonication at room temperature through coupling between the Ti-O-C bond and electrostatic interaction. The C-dots can dramatically enhance the absorption of the composite by forming the DZS, and the composite is enabled to generate more free radicals, which facilitate ∼10 times higher photocatalytic activity compared to that of TiO2. As a proof of concept, the as-prepared C-dot/TiO2 was used for textile wastewater dye degradation. This study provides an efficient approach for room-temperature preparation of C-dot/TiO2 composites with high photocatalytic activity.

Boosting Photocatalytic Activity Using Vanadium Doped Titanium Oxide with Reduced Graphene Oxide (RGO)/Semiconductor Nanocomposites

Textile waste materials are increasing day by day with the depletion of water. This increasing concentration of ions, functional groups, and ammonia present in the water as a byproduct from the industries produce toxicity. This affects the human and aquatic life. The sustainability of the materials to rule out this toxicity can be done by Reduced Graphene Oxide synthesized by modified Hummer’s method. The composite of V-doped TiO2 and RGOwas synthesized by hydrothermal method and V-doped TiO2/RGOand perfluorocarbon synthesized by sonication. Methylene blue was used as an indicator to improve the pH of the wastewater under sunlight. The product was characterized by the powder X-ray Diffraction method. It has confirmed the synthesis of the product. The ultraviolet/visible spectroscopy was employed to study the absorbance decreases with time which is the confirmation of degradation of methylene blue with time and it was clearly observed that photocatalytic activity of the product for the degradation of methylene blue which is an organic dye and hazardous to the environment. The findings obtained can be utilize for the industrial waste-water treatment with metallic ions.