Sulfur-doped Graphitic Carbon Research Articles

Highly selective and sensitive Pb2+ detection via sulfur-doped graphitic carbon nitride modified by Bi nanospheres

The present-day human race is facing a series of environmental problems due to sewage discharge, excessive use of chemicals, mineral exploitation and so on, which are closely related to the rapid development of industries. The direct consequence is that the pollution of heavy metal ions is becoming more and more serious. It is very important to develop sensitive and efficient methods for detecting heavy metal ions. In this study, the nanocomposite of sulfur-doped graphitic carbon nitride (SCN) and Bi nanospheres (BiNSs) was prepared by thermal polycondensation reaction to introduce the sulfur into carbon nitride, followed by solvothermal method to realize the decoration of BiNSs. The SCN/BiNSs nanocomposite presents a highly selective and sensitive electrochemical detection capacity for Pb2+, derived from S-Pb strong bonding interaction and Bi-Pb binary alloy formation. The low detection limit of 0.07 μM could be achieved when the current response of Pb2+ was measured in the linear range of 0.1 μM − 4.5 μM by square wave anodic stripping voltammetry. The detection of Pb2+ in actual water specimens led to a recovery rate varied from 88 to 123 %. Further, in the presence of 20-fold interfering ions such as Zn2+, Fe3+, Cd2+, Cu2+, Fe2+ and Ni2+, the SCN/BiNSs-modified electrode still possesses excellent immunity and selectivity. Meanwhile, the remarkable stability, repeatability and reproducibility of the above sensing electrode have also been demonstrated. Our primary results show that the SCN/BiNSs nanocomposite holds great potential for practical application for Pb2+ detection.

Unveiling carcinogenic pollutant levels in environmental water samples through facile fabrication of gold nanoparticles on sulfur-doped graphitic carbon nitride

Extensive utilization of pesticides and herbicides to boost agricultural production increased the environmental health risks, which can be mitigate with the aid of highly sensitive detection systems. In this study, an electrochemical sensor for monitoring the carcinogenic pesticides in the environmental samples has been developed based on sulfur-doped graphitic-carbon nitride–gold nanoparticles (SCN-AuNPs) nanohybrid. Thermal polycondensation of melamine with thiourea followed by solvent exfoliation via ultrasonication leads to SCN formation and electroless deposition of AuNPs on SCN leads to SCN-AuNPs nanohybrid synthesis. The chemical composition, S-doping, and the morphology of the nanohybrid were confirmed by various microscopic and spectroscopic tools. The as-synthesized nanohybrid was fabricated with glassy carbon (GC) electrode for determining the carcinogenic hydrazine (HZ) and atrazine (ATZ) in field water samples. The present sensor exhibited superior electrocatalytic activity than GC/SCN and GC/AuNPs electrodes due to the synergism between SCN and AuNPs and the amperometric studies showed the good linear range of detection of 20 nM–0.5 mM and 500 nM–0.5 mM with the limit of detection of 0.22 and 69 nM (S/N = 3) and excellent sensitivity of 1173.5 and 13.96 μA mM−1 cm−2 towards HZ and ATZ, respectively. Ultimately, the present sensor is exploited in environmental samples for monitoring HZ and ATZ and the obtained results are validated with high-performance liquid chromatography (HPLC) technique. The excellent recovery percentage and close agreement with the results of HPLC analysis proved the practicability of the present sensor. In addition, the as-prepared materials were utilized for the photocatalytic degradation of ATZ and the SCN-AuNPs nanohybrid exhibited higher photocatalytic activity with the removal efficiency of 93.6% at 90 min. Finally, the degradation mechanism was investigated and discussed.

Nonenzymatic electrochemical approaches for promethazine monitoring in aquatic media

Promethazine hydrochloride (PMH) is a phenothiazine derivative extensively utilized in healthcare settings. Its excessive consumption and continuous release into environmental water bodies can lead to adverse effects on human health and disrupt the equilibrium of aquatic ecosystems. Therefore, monitoring PMH levels is essential to maintain therapeutic efficacy and safeguard the well-being of both humans and aquatic life. This study encompasses the synthesis of samarium tungstate nanorods (SmWO) via hydrothermal method, followed by their incorporation into a composite with sulfur-doped graphitic carbon nitride (SmWO/SGCN) using ultrasonication technique. The morphology and physicochemical properties of the synthesized composite were thoroughly examined using various analytical methods. Subsequently, the electrocatalytic activity of the developed sensor was assessed for sensing PMH via voltammetry techniques. Under optimized conditions, the fabricated electrode exhibited an 8.1 nM detection limit with a wide linear range (0.02–199 µM), and high sensitivity (2.349 µA µM−1 cm−2) for PMH detection. The suggested SmWO/SGCN composite electrode shows promising practical potential for detecting PMH in environmental aquatic samples.

Sustainable energy generation: High-performance NiCo2S4@S-g-C3N4 bifunctional electrocatalyst advances water splitting efficiency

Efforts to create cost-effective electrocatalysts from abundant materials, for the utilization of water electrolysis reactions, are viewed as promising sources for sustainable clean energy generation. This article describes the synthesis of cobalt sulphide (CoS) nanoparticles using a straightforward and environmentally friendly one-pot hydrothermal process. The series of nickel-doped CoS (NiCo2-x S4) introduced with varying the weight percentage of Ni (1, 2, 4, 8, 6, and 10 wt%), and the composite Ni-dopped CoS on varying the weight percentage (10, 30, 50, 70, and 90 wt %) of sulfur-doped graphitic carbon nitride (NiCo2S4@S-g-C3N4) was created. Utilizing X-ray diffraction analysis (XRD), EDS, FTIR, and scanning electron microscopy (SEM) synthesized electrocatalysts were characterized. Doped with Fluorine After being changed with an electrocatalyst, tin oxide was used as the working electrode to monitor the electrochemical activity of the whole water splitting process using chronopotentiometry, cyclic voltammetry (CV), linear sweep voltammetry (LSV), and EIS. NiCo2S4@S-g-C3N4 exhibited higher electrocatalytic performance with an overpotential 370 mV for OER and 415 mV for HER at the current intensity of 10 mAcm−2. Transition metal sulfide electrocatalysts exhibit good electrolytic performance, due to their high surface areas and intrinsically high catalytic activity. These findings suggest that the NiCo2S4@S-g-C3N4 composite possesses a significant role for use in energy conversion and energy storage applications.

A Novel Molecularly Imprinted Quartz Crystal Microbalance Sensor Based on Erbium Molybdate Incorporating Sulfur-Doped Graphitic Carbon Nitride for Dimethoate Determination in Apple Juice Samples.

Dimethoate (DIM) as an organophosphorus pesticide is widely utilized especially in the cultivation of vegetables and fruits due to its killing effect on harmful insects. However, unconscious use of DIM in large amounts can also cause serious health problems. For these reasons, rapid and reliable detection of DIM from food samples is significant. In this study, a novel quartz crystal microbalance (QCM) sensor based on erbium molybdate incorporating sulfur-doped graphitic carbon nitride (EM/S-g-C3N4) and a molecularly imprinting polymer (MIP) was designed for DIM detection in apple juice samples. Firstly, an EM/S-g-C3N4 nanocomposite with high purity was prepared under hydrothermal conditions at high temperatures over a long period of time. After the modification of the EM/S-g-C3N4 nanocomposite on a QCM chip, the polymerization solution including N,N'-azobisisobutyronitrile (AIBN) as an initiator, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, methacryloylamidoglutamic acid (MAGA) as a monomer, and DIM as an analyte was prepared. Then, the polymerization solution was dropped on an EM/S-g-C3N4 nanocomposite modified QCM chip and an ultraviolet polymerization process was applied for the formation of the DIM-imprinted polymers on the EM/S-g-C3N4 nanocomposite modified QCM chip. After the polymerization treatment, some characterization studies, including electrochemical, microscopic, and spectroscopic methods, were performed to illuminate the surface properties of the nanocomposite and the prepared QCM sensor. The values of the limit of quantification (LOQ) and the detection limit (LOD) of the prepared QCM sensor were as 1.0 × 10-9 M and 3.3 × 10-10 M, respectively. In addition, high selectivity, stability, reproducibility, and repeatability of the developed sensor was observed, providing highly reliable analysis results. Finally, thanks to the prepared sensor, it may be possible to detect pesticides from different food and environmental samples in the future.

Copper sulfide-incorporated layered porous sulfur-doped graphitic carbon nitride nanosheets for an efficient catalytic reduction of 4-nitrophenol

A straightforward one-pot synthesis of CuS nanoparticles directly grown on layered porous sulfur-doped graphitic carbon nitride nanosheets (CuS/S-g-C3N4) acts as a catalyst for the reduction of 4-nitrophenol.

Fenpicoxamid-Imprinted Surface Plasmon Resonance (SPR) Sensor Based on Sulfur-Doped Graphitic Carbon Nitride and Its Application to Rice Samples.

This research attempt involved the development and utilization of a newly designed surface plasmon resonance (SPR) sensor which incorporated sulfur-doped graphitic carbon nitride (S-g-C3N4) as the molecular imprinting material. The primary objective was to employ this sensor for the quantitative analysis of Fenpicoxamid (FEN) in rice samples. The synthesis of S-g-C3N4 with excellent purity was achieved using the thermal poly-condensation approach, which adheres to the principles of green chemistry. Afterwards, UV polymerization was utilized to fabricate a surface plasmon resonance (SPR) chip imprinted with FEN, employing S-g-C3N4 as the substrate material. This process involved the inclusion of N,N'-azobisisobutyronitrile (AIBN) as the initiator, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, methacryloylamidoglutamic acid (MAGA) as the monomer, and FEN as the analyte. After successful structural analysis investigations on a surface plasmon resonance (SPR) chip utilizing S-g-C3N4, which was imprinted with FEN, a comprehensive investigation was conducted using spectroscopic, microscopic, and electrochemical techniques. Subsequently, the kinetic analysis applications, namely the determination of the limit of quantification (LOQ) and the limit of detection (LOD), were carried out. For analytical results, the linearity of the FEN-imprinted SPR chip based on S-g-C3N4 was determined as 1.0-10.0 ng L-1 FEN, and LOQ and LOD values were obtained as 1.0 ng L-1 and 0.30 ng L-1, respectively. Finally, the prepared SPR sensor's high selectivity, repeatability, reproducibility, and stability will ensure safe food consumption worldwide.

Fabrication of direct Z-scheme heterojunction of S doped g-C3N4/Ag/AgI for efficient dye degradation

In this work, we scrutinized the photodegradation ability of a novel composite material, sulfur-doped graphitic carbon nitride/Ag/AgI (SCN/Ag/AgI) for methylene blue (MB) dye degradation. The SCN/Ag/AgI nanocomposite was fabricated by a cost-effective co-precipitation method. The fabricated SCN/Ag/AgI nanocomposite exhibited significantly enhanced photocatalytic activity i.e. 88% MB degradation rate. The SCN/Ag/AgI heterojunction followed a direct Z-scheme charge transferal channel in which Ag worked as an electron mediator. Furthermore, •OH and •O2– radicals reactive species were formed that efficiently destroyed MB pollutants.

Voltammetric nano-molar range quantification of agrochemical pesticide using needle-like strontium pyrophosphate embedded on sulfur doped graphitic carbon nitride electrocatalyst

The development of a viable sensor for agrochemical pesticides requires the assessment of trace levels. To achieve this, we developed a diphenylamine (DPA) sensor using needle-like strontium pyrophosphate embedded in sulfur-doped graphitic carbon nitride (SrPO/SCN). We obtained needle-like SrPO/SCN nanocomposite through co-precipitation followed by ultrasonication. The formation of the SrPO/SCN nanocomposite was verified through FT-IR, XRD, XPS, SEM-EDX, and HR-TEM analyses. Additionally, we explored their electrochemical behavior towards DPA using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The SrPO/SCN nanocomposite-modified electrode exhibited a higher anodic peak current (15.47 µA) than those of the other modified and unmodified electrodes. Under optimal experimental conditions, SrPO/SCN/GCE demonstrated a good limit of detection (0.009 µmol/L), dynamic linear range (0.05–98 µmol/L), and sensitivity (0.36 µAµM-1cm−2). Furthermore, the developed sensor exhibited excellent reproducibility, selectivity, and stability, and successfully detected DPA in real samples, including pear and apple samples, with good recoveries.

Green reduction and uniform assembly of silver nanoparticles on polydopamine functionalized sulfur-doped graphitic carbon nitride nanosheets for highly sensitive H2O2 detection via nonenzymatic approach

In this study, we demonstrate a new strategy to fabricate an enzyme-free hydrogen peroxide (H2O2) sensor electrode based on silver nanoparticles (AgNPs) decorated polydopamine/sulfur-doped graphitic carbon nanocomposite (denoted as AgNPs@PDA/S-g-C3N4). The S-g-C3N4 nanosheets are derived from the pyrolysis of trithiocyanouric acid, followed by thermal exfoliation. A mussel-inspired PDA nanolayer enhances the solubility and high dispersion of S-g-C3N4 nanosheets and AgNPs in aqueous phase synthesis. The amine and catecholic functional groups of PDA are the major nucleation sites for Ag+ ions adsorption and ascorbic acid was further used as a green reducing agent for the growth of AgNPs. PDA adhesion layer can effectively connect the AgNPs and S-g-C3N4 nanosheets via electrostatic interaction to increase the stability and biocompatibility of the ternary composite structure. Various spectroscopy and microscopy techniques confirmed the formation of AgNPs@PDA/S-g-C3N4 nanocomposite. Our AgNPs@PDA/S-g-C3N4 nanocomposite fabricated disposable sensor exhibited outstanding sensing ability to H2O2 reduction at −0.65 V (vs. Ag/AgCl), which is confirmed through an amperometric detection method. The sensor exhibits rapid response (2 s) to H2O2 sensing with high sensitivity (1020 μA mM−1 cm−2), wide detection range (0.002–23 mM) and low limit of detection of 0.086 μM. The practicality of the H2O2 sensor was evaluated with commercial milk and mouthwash samples, which retained satisfactory recoveries. Thus, our results indicate that the PDA functionalization not only enhances the S-g-C3N4 solubility but also increases the interfacial charge transport in AgNPs@PDA/S-g-C3N4 nanocomposite material which develops a potential sensing method for nonenzymatic H2O2 sensor. Due to the effective surface modification strategies, such as PDA nanocoating and AgNPs deposition, the exfoliated S-g-C3N4 nanosheets gained excellent electrochemical properties, facilitating potential candidates in electrochemical applications.

3D ordered macroporous sulfur-doped g-C3N4/TiO2 S-scheme photocatalysts for efficient H2O2 production in pure water

Photocatalytic hydrogen peroxide (H2O2) production offers a clean and cost-efficient alternative to the traditional anthraquinone oxidation approach. Herein, a step-scheme (S-scheme) heterojunction photocatalyst is fabricated by coupling TiO2 with three dimensionally ordered macroporous sulfur-doped graphitic carbon nitride (3DOM SCN/T) by electrostatic self-assembly. The optimized photocatalyst achieved a high photocatalytic H2O2 production activity with a yield of 2128 μmol h−1g−1 without the addition of hole scavengers. The remarkable performance was attributed to the synergy between the 3DOM framework and the S-scheme heterojunction. The former enhances light harvesting and provides abundant active sites for surface reactions, while the latter promotes the spatial separation of photogenerated carriers and enhances the redox power. Finally, the mechanism of photocatalytic H2O2 production over the 3DOM SCN/T S-scheme composite is proposed. This work provides novel insights into the development of efficient photocatalysts for H2O2 production from water and O2.

Photothermal-enabled single-atom catalysts for high-efficiency hydrogen peroxide photosynthesis from natural seawater

Hydrogen peroxide (H2O2) is a powerful industrial oxidant and potential carbon-neutral liquid energy carrier. Sunlight-driven synthesis of H2O2 from the most earth-abundant O2 and seawater is highly desirable. However, the solar-to-chemical efficiency of H2O2 synthesis in particulate photocatalysis systems is low. Here, we present a cooperative sunlight-driven photothermal-photocatalytic system based on cobalt single-atom supported on sulfur doped graphitic carbon nitride/reduced graphene oxide heterostructure (Co–CN@G) to boost H2O2 photosynthesis from natural seawater. By virtue of the photothermal effect and synergy between Co single atoms and the heterostructure, Co–CN@G enables a solar-to-chemical efficiency of more than 0.7% under simulated sunlight irradiation. Theoretical calculations verify that the single atoms combined with heterostructure significantly promote the charge separation, facilitate O2 absorption and reduce the energy barriers for O2 reduction and water oxidation, eventually boosting H2O2 photoproduction. The single-atom photothermal-photocatalytic materials may provide possibility of large-scale H2O2 production from inexhaustible seawater in a sustainable way.

Insights into the Electrocatalytic Oxygen Evolution Reaction and Photocatalytic Methylene Blue Degradation of Mixed Spinel NixCu1–xFe2O4 Nanocomposites Anchored at Sulfur-Doped g-C3N4

In consideration of energy conversion and/or environmental protection, it is important to develop electrocatalytic and/or photocatalytic active materials for the oxygen evolution reaction (OER) and photodegradation of methylene blue (MB), respectively. To meet these requirements, mixed spinel ferrites such as NixCu1–xFe2O4 anchored at sulfur-doped graphitic carbon nitride (SCN) nanosheets was developed for the first time via a simple one-pot hydrothermal method for the construction of a novel bifunctional NixCu1–xFe2O4@SCN nanocomposite. Initially, the crystal structure, optical properties, surface morphology, elemental composition, and surface area of different nanocomposites, such as NiFe2O4, Ni0.8Cu0.2Fe2O4, Ni0.5Cu0.5Fe2O4, Ni0.2Cu0.8Fe2O4, SCN, and Ni0.5Cu0.5Fe2O4@SCN, were studied through XRD, UV-DRS analysis, FT-IR, FE-SEM with EDX, HR-TEM, and BET analysis. Furthermore, when compared to other prepared electrode nanocomposites such as spinel ferrites or different proportion mixed spinel ferrites, the Ni0.5Cu0.5Fe2O4@SCN nanocomposite loaded 316 SSL mesh electrode demonstrated exceptional electrocatalytic oxygen evolution performance with a very low overpotential of 250 mV at 10 mA cm–2 current density and outstanding stability. Subsequently, the photocatalytic activities of the prepared mixed spinel ferrites, NixCu1–xFe2O4@SCN nanocomposites, were tested through the degradation of MB under visible-light irradiation. Among the prepared photocatalysts, Ni0.5Cu0.5Fe2O4@SCN nanocomposite showed superior photocatalytic MB degradation under visible light, which is firmly due to the equi-proportion blending of Cu+2 substitutions in mixed spinel ferrites at SCN. Accordingly, the Ni0.5Cu0.5Fe2O4@SCN nanocomposite shows excellent photocatalytic degradation (POD) efficiency of 99.1% for MB in 40 min, while other nanocomposites such as NiFe2O4, SCN, and Ni0.5Cu0.5Fe2O4 show 40.2, 42.5, and 91.2% degradation efficiencies, respectively. Thus, the Ni0.5Cu0.5Fe2O4@SCN nanocomposite could be a promising material for electrocatalytic OER and/or photocatalytic degradation of MB under visible-light irradiation.

Synergetic effects of Mo2C sphere/SCN nanocatalysts interface for nanomolar detection of uric acid and folic acid in presence of interferences

Till to date, the application of sulfur-doped graphitic carbon nitride supported transition metal carbide interface for electrochemical sensor fabrication was less explored. In this work, we designed a simple synthesis of molybdenum carbide sphere embedded sulfur doped graphitic carbon nitride (Mo2C/SCN) catalyst for the nanomolar electrochemical sensor application. The synthesized Mo2C/SCN nanocatalyst was systematically characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with elemental mapping. The SEM images show that the porous SCN network adhered uniformly on Mo2C, causing a loss of crystallinity in the diffractogram. The corresponding elemental mapping of Mo2C/SCN shows distinct peaks for carbon (41.47%), nitrogen (32.54%), sulfur (1.37%), and molybdenum (24.62%) with no additional impurity peaks, reflecting the successful synthesis. Later, the glassy carbon electrode (GCE) was modified by Mo2C/SCN nanocatalyst for simultaneous sensing of uric acid (UA) and folic acid (FA). The fabricated Mo2C/SCN/GCE is capable of simultaneous and interference free electrochemical detection of UA and FA in a binary mixture. The limit of detection (LOD) calculated at Mo2C/SCN/GCE for UA and FA was 21.5 nM (0.09 – 47.0 μM) and 14.7 nM (0.09 – 167.25 μM) respectively by differential pulse voltammetric (DPV) technique. The presence of interferons has no significant effect on the sensor’s performance, making it suitable for real sample analysis. The present method can be extended to fabricate an electrochemical sensor for various molecules.

Fe-Fe Double-Atom Catalysts for Murine Coronavirus Disinfection: Nonradical Activation of Peroxides and Mechanisms of Virus Inactivation.

Peroxides find broad applications for disinfecting environmental pathogens particularly in the COVID-19 pandemic; however, the extensive use of chemical disinfectants can threaten human health and ecosystems. To achieve robust and sustainable disinfection with minimal adverse impacts, we developed Fe single-atom and Fe-Fe double-atom catalysts for activating peroxymonosulfate (PMS). The Fe-Fe double-atom catalyst supported on sulfur-doped graphitic carbon nitride outperformed other catalysts for oxidation, and it activated PMS likely through a nonradical route of catalyst-mediated electron transfer. This Fe-Fe double-atom catalyst enhanced PMS disinfection kinetics for inactivating murine coronaviruses (i.e., murine hepatitis virus strain A59 (MHV-A59)) by 2.17-4.60 times when compared to PMS treatment alone in diverse environmental media including simulated saliva and freshwater. The molecular-level mechanism of MHV-A59 inactivation was also elucidated. Fe-Fe double-atom catalysis promoted the damage of not only viral proteins and genomes but also internalization, a key step of virus lifecycle in host cells, for enhancing the potency of PMS disinfection. For the first time, our study advances double-atom catalysis for environmental pathogen control and provides fundamental insights of murine coronavirus disinfection. Our work paves a new avenue of leveraging advanced materials for improving disinfection, sanitation, and hygiene practices and protecting public health.

An efficient polydopamine modified sulphur doped GCN photocatalyst for generation of HCOOH from CO2 under sun ray irradiation

The photocatalytic transformations of CO2 into solar chemicals are a promising way in views of green energy and environmental sustainability. Improving the low catalytic performance and poor selectivity of the photocatalysts are one of the great challenges in this field. By mimicking the natural photosynthesis and taking advantage of the enzyme’s high specificity and efficiency, we designed the metal-free photocatalyst combined to an enzyme in order to synergistically solve the stated problems. In this work, we developed a metal-free polydopamine (P) modified sulfur-doped graphitic carbon nitride (P@SGCN) photocatalyst for the regeneration of NADH and the highly selective production of formic acid, HCOOH, from CO2. Our study shows a new way for the applications of polydopamine-modified photocatalysts to produce the solar chemicals/fuels from CO2.

Fabrication of Effective Co-SnO2/SGCN Photocatalysts for the Removal of Organic Pollutants and Pathogen Inactivation

Substantial improvement is needed in efficient and affordable decolorization and disinfection methods to solve the issues caused by dyes and harmful bacteria in water and wastewater. This work involves the photocatalytic degradation of methylene blue (MB) as well as gram-negative and gram-positive bacteria by cobalt-doped tin oxide (Co-SnO2) nanoparticles (NPs) and Co-SnO2/SGCN (sulfur-doped graphitic carbon nitride) nanocomposites (NCs) under sunlight. The coprecipitation approach was used to synthesize the photocatalysts. Maximum methylene blue (MB) photocatalytic degradation was seen with the 7% Co-SnO2 NPs compared to other (1, 3, 5, and 9 wt.%) Co-SnO2 NPs. The 7% Co-SnO2 NPs were then homogenized with different amounts (10, 30, 50, and 70 weight %) of sulfur-doped graphitic carbon nitride (SGCN) to develop Co-SnO2/SGCN heterostructures with the most significant degree of MB degradation. The synthesized samples were identified by modern characterization methods such as FT-IR, SEM, EDX, UV-visible, and XRD spectroscopies. The Co-SnO2/50% SGCN composites showed a significant increase in MB degradation and degraded 96% of MB after 150 min of sunlight irradiation. Both gram-negative (E. coli) and gram-positive (B. subtiles) bacterial strains were subjected to antibacterial activity. All samples were shown to have vigorous antibacterial activity against gram-positive and gram-negative bacteria, but the Co-SnO2/50% SGCN composites exhibited the maximum bactericidal action. Thus, the proposed NC is an efficient organic/inorganic photocatalyst that is recyclable and stable without lowering efficiency. Hence, Co-SnO2/50% SGCNNC has the potential to be employed in water treatment as a dual-functional material that simultaneously removes organic pollutants and eradicates bacteria.

Self-Assembled Hierarchical Silkworm-Type Bimetallic Sulfide (NiMo3S4) Nanostructures Developed on S-g-C3N4 Sheets: Promising Electrode Material for Supercapacitors

An electrode material composed of bimetallic sulfides on g-C3N4 typically enhances the energy storage capacity of devices due to the merits of each component, but it still suffers from low energy density over long cycles. Although Ni-based bimetallic sulfides have become good electrode materials for supercapacitors, practical applications of these materials are hindered due to unsatisfactory cycling stability. Here, we demonstrate a simple two-step in situ approach to prepare bimetallic sulfide nanobulbs on a sulfur-doped graphitic carbon nitrate matrix for a NiMo3S4@S-g-C3N4 composite, which is further used for supercapacitor devices. A small amount of sulfur doping to g-C3N4 enhances the conducting channels for electron transportation. An NMS@S-gC nanocomposite clearly shows the formation of small nanobulbs that are formed as silk warm-type hierarchical morphology structures and these were wrapped on the surface of S-gC porous nanosheets. The device made up of these composites exhibited a maximum specific capacitance of 142.4 F g–1, a high energy density of 41.4 Wh kg–1, and a power density of 723.5 W kg–1 at a current density of 1 A g–1. Meanwhile, in a three-electrode device configuration, the working electrode demonstrates a specific capacitance of 934.2 F g–1 at 1 A g–1, which is 1.6 times greater than that of bare NiMo3S4. Moreover, the capacitance retention of the device is about 91% even after 5000 cycles at 8 A g–1. The results obtained in this investigation surpassed most reported metallic sulfides on g-C3N4. Hence, this work could give a different pathway for the synthesis of electrode materials for energy storage devices.

Zero-Biased and Visible Light-Driven Immunosensing of Cardiac Troponin I Biomarker Based on a BiOI/S-g-C3N4/Bi-NaTaO3 Photoelectrochemical Platform

This work describes the development of a platform based on bismuth oxyiodide (BiOI), sulfur-doped graphitic carbon nitride (S-g-C3N4), and bismuth-doped sodium tantalate perovskite (Bi-NaTaO3) for zero-biased photoelectrochemical immunosensing of cardiac troponin I (cTnI) biomarker. The spectroscopic, structural, morphological, and compositional characteristics of the photoelectrochemical (PEC) materials were evaluated by Raman and Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical impedance (EI) measurements were performed under the incidence and absence of light to investigate the effects of photons on the charge transfer resistance of the photoelectrochemical platform. The influence of the cTnI biomarker on the photoelectrochemical response of the anti-cTnI antibody-modified photoelectrochemical platform (anti-cTnI/BiOI/S-g-C3N4/Bi-NaTaO3/FTO) was evaluated by measuring the photocurrent of the system. The immunosensor presented a linear response range from 1 pg mL-1 to 50 ng mL-1, mean recovery percentage between 95.98 and 99.78% in real human serum samples, and selectivity for the cTnI biomarker.

Improved visible light-driven photocatalytic degradation of an industrial dye Acid Orange 7 using metal-free sulfur-doped graphitic carbon nitride

Sulfur-doped graphitic carbon nitride (SGCN) is prepared by thermal polymerization and utilized for industrial Acid Orange 7 (AO-7) degradation.