3N4 Composites Research Articles

Synthesis of tin selenide nanoparticles using Polygonum avicular extract decorated on graphitic carbon nitride for enhancing photodegradation of amoxicillin trihydrate and photoproduction of hydrogen peroxide

In this research, tin selenide nanoparticles (SnSe-NPs) were synthesized using Polygonum avicular extract via the hydrothermal method and decorated on graphitic carbon nitride (g-C3N4) by the simple sonicated method to produce SnSe/g-C3N4 composites. The characterization and properties of the SnSe/g-C3N4 composites, as compared to pristine SnSe and g-C3N4, were determined by Fourier-transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscope, transmission electron microscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, Mott-Schottky, and electrochemical impedance spectroscopy. As a result, the SnSe-NPs possessed the rod-like shape and after the decoration onto the g-C3N4 sheet surface, it reduced the bandgap energy of the g-C3N4 from 2.58 downward 1.43 eV. Besides, the photoactivities of the 10-SnSe/g-C3N4 catalyst were investigated via both sides of amoxicillin trihydrate (AMXT) photodegradation and hydrogen peroxide (H2O2) photoproduction, in which the results were achieved 87.84 % AMXT and 85.48 μM H2O2, respectively, under visible light. Furthermore, the photodegradation was consistent with the pseudo-first-order kinetics and it performed the highest photodegradation at pH ∼5, while the importance of isopropyl alcohol as a trapping agent and •O2− radicals was affirmed in the H2O2 photoproduction. Moreover, the photoproduction of H2O2 was remained after 4 cycles achieved at 62.70 % in the final cycle, which demonstrated the stability and reusability of the 10-SnSe/g-C3N4. These aforementioned results demonstrate that the SnSe/g-C3N4 material is a promising candidate for addressing environmental pollution and energy scarcity issues.

Efficient tetracycline removal from hospital wastewater using visible light active M-type lead hexaferrite/g-C3N4 composites

Efficient tetracycline removal from hospital wastewater using visible light active M-type lead hexaferrite/g-C3N4 composites

Alginate/CuO-gC3N4 composite: a novel, reusable, non-toxic photocatalyst for methylene blue degradation.

Increasing industrial contamination necessitates development of sustainable water treatment solutions. Photocatalysis is a green technology utilizing light-activated materials (photocatalysts), which can degrade pollutants into harmless by-products. It is an emergent need to develop a photocatalyst that presents a significant advancement for sustainable water treatment and non-toxic to the environment. This study investigates the photocatalytic activity and in vitro cytotoxicity of a novel hybrid material comprising of alginate, copper oxide (CuO) and graphitic carbon nitride (gC3N4) for methylene blue (MB) degradation. The hybrid material was synthesized by a two-step process: (i) doping of CuO on gC3N4 through co-precipitation method formed CuO-gC3N4 (CG) and (ii) incorporation of CG in the calcium alginate (A) by ionotropic gelation method that is named as ACG. The characteristic features of the synthesized A, CG and ACG were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The optical characteristic of A, CG and ACG was studied using UV-diffuse reflectance spectroscopy (UV-DRS). The morphology and elemental composition of ACG was evaluated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). To assess the environmental impact of ACG, a two-step approach was employed. First, the photocatalytic activity of ACG under UV-visible light (UV-vis) irradiation for MB degradation was evaluated. ACG exhibited photocatalytic activity by achieving 86.26% of degradation efficiency for MB within 60min. Second, the in vitro cytotoxicity of ACG, MB and MB degraded products towards tilapia gill cell lines were assessed. By comparing the toxicity of the MB and the secondary products, it is concluded that the overall process leads to a sustainable outcome.

Efficient photocatalytic CO2 and Cr(VI) reduction on carbon spheres/g-C3N4 composites with enriched nitrogen vacancies

In this study, carbon spheres (CS)/g-C3N4 composite materials were fabricated by a hydrothermal method, and the characterizations have confirmed the successful anchoring of CS onto the surface of g-C3N4, constructing enriched nitrogen vacancies during the synthesis process. The photocatalytic CO2 reduction activity of g-C3N4 is enhanced by all of these advantageous factors. The significant enhancement can be attributed to the tight interfacial interaction between CS and g-C3N4, which endows with the photocatalyst a larger specific surface area, higher light utilization efficiency and stronger capability for photoinduced charges separation. Furthermore, the presence of nitrogen vacancies further accelerates the separation and migration efficiency of photogenerated charges, provides additional active sites to promote the adsorption and activation of CO2 molecules, thereby effectively boosting the photocatalytic activity for CO2 reduction. The CO2 conversion rate on CS/g-C3N4 composite materials is higher than that on the reference g-C3N4. The apparent quantum yield (AQY) is also superior to that of the reference g-C3N4 under three different monochromatic light irradiations. The stability of the catalyst was verified through cycling experiments, indicating promising potential practical industrial application. The CO2 reduction mechanism and transformation pathways were elucidated using in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The photocatalytic reduction rate constant of Cr(VI) by 50CS/CN is 2.9 times higher than that by CN. This study introduces a facile approach for synthesizing g-C3N4-based photocatalytic materials, providing an interesting strategy to boost photocatalytic activity of g-C3N4 for photocatalytic CO2 and Cr(VI) reduction.

Ag2Se nanoparticles anchored on S-g-C3N4 nanosheets towards efficient photocatalytic tetracycline hydrochloride removal and H2 generation

To improve the stability of Ag based co-catalysts and to increase the photocatalytic performance of graphitic carbon nitride (g-C3N4), Ag2Se nanoparticles were grown onto superior thin sulfur-doped g-C3N4 nanosheets which was fabricated via two-step thermal polymerization at high temperature. Ultrathin S-doped g-C3N4 nanosheets were prepared via two-step thermal polymerization using melamine and thiourea. The ratios of Ag2Se were adjusted to fabricate a series of Ag2Se/S-g-C3N4 (Ag2Se/SCN) composite samples by controlled solvothermal synthesis. S-doping plays an important role in mono-dispersion of Ag2Se nanoparticles on S-g-C3N4 nanosheets because of the control of growth sites. The photocatalytic removal of tetracycline hydrochloride test indicates that sample Ag2Se/SCN-3 with Ag2Se loading of 3 % reveals the best removal effect, in which tetracycline hydrochloride of 60 % is removed within 60 min. Photocatalytic hydrogen generation test results without co-catalyst addition demonstrate that sample Ag2Se/SCN-3 exhibits the best H2 evolution rate of 2116.35 μmol·g−1·h−1, which is 3.8 times of that of pure carbon nitride. The photocatalytic mechanism tests suggest that Schottky heterojunctions are formed in the Ag2Se/S-g-C3N4 composites. The formation of Schottky heterojunctions improved the separation efficiency of photogenerated charge carriers. The incorporation of Ag2Se nanoparticles (as the co-catalyst) on S-g-C3N4 nanosheets is the key for drastically improving the photocatalytic performance and eliminating the use of Pt co-catalyst during the photocatalytic processes.

Enhancement of peroxymonosulfate activation through regulating electronic structure of cobalt phthalocyanine by g-C3N4 for rhodamine B degradation

The catalytic performance of cobalt-based catalysts in Fenton-like reactions is significantly influenced by the electron density of Co centers. However, precise control of the electronic structure to enhance the degradation activity remains a challenge. This paper demonstrates a method to enhance the catalytic activity of cobalt phthalocyanine (CoPc) by modulating its electronic structure via integrating with graphitic carbon nitride (g-C3N4). The electron redistribution between g-C3N4 and CoPc was observed, resulting in electron-rich Co centers. Consequently, the CoPc/g-C3N4 composites exhibit significantly enhanced peroxymonosulfate (PMS) activation capability compared to CoPc and their physical mixtures. The improved catalytic performance is due to the electron-rich Co centers, better dispersion of CoPc, and enhanced hydrophilicity. This study proposes a novel strategy for the design of efficient PMS activation catalysts.

Effectively enhanced photocatalytic hydrogen production performance of novel noble metal-free Cu(OH)2/MoSe2-g-C3N4 ternary nanocomposite under visible light irradiation

The present work presents a novel copper hydroxide-molybdenum diselenide-carbon nitride (3 % Cu(OH)2/MoSe2-g-C3N4, (3CM-CN)) ternary nanocomposite catalyst. This catalyst was synthesized using a three-step process: hydrothermal synthesis, ball milling, and wet impregnation. The focus of this research is on the hydrogen generation (H₂) capabilities of this novel material. The catalyst was extensively characterized using various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS), resulting in a comprehensive understanding of its structure, morphology, optical properties, and surface composition. The catalytic activity and mechanism of Cu(OH)2/MoSe2-g-C3N4 composites were investigated. The ternary nanocomposite catalyst significantly enhanced hydrogen production, achieving rates 7.7 times greater than g-C3N4 and 4 times greater than 3 % Cu(OH)2/MoSe2 (3CM). Its maximum production reached an impressive 3012 µmol g−1 h−1. The analysis demonstrated a significant increase in active sites on the composite’s surface, accompanied by an increase in the composite-specific surface area to 73 m2/g. The development of a ternary nanocomposite led to a higher rate of catalyst production for hydrogen generation while simultaneously decreasing the rate of electron-hole recombination. It gave an innovative strategy for constructing highly efficient composite catalysts for hydrogen generation very effectively.

LaxNiy Mn2-(x+y)O3/g-C3N4 composite: A multifunctional material for photocatalytic and adsorptive removal of pollutants with statistical evaluation

The disposal of tons of organic chemicals annually in water resources is an alarming threat to the environment. Among the various remediation techniques, the combination of adsorption and degradation is a highly effective and economical strategy for eliminating these contaminants. In this study, a novel LaxNiyMn2-(x+y)O3/g-C3N4 composite [x,y = (0.00,0.00), (0.03,0.06), (0.06,0.03), (0.045,0.045)] is synthesized by a low-temperature and cost-efficient sol-gel auto-combustion method to address this issue. Field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) were used to characterize the morphology and crystal structure of the composite, respectively. The optical properties of the composite were investigated by a UV–visible spectrophotometer. The photocatalytic performance of the prepared samples was evaluated against crystal violet and 4-nitrophenol under solar irradiation. The doped composite La0.06Ni0.03Mn1.91O3/g-C3N4 exhibited superior degradation efficiency of 87.54 % for crystal violet in 60 min, compared to 56.2 % for the undoped composite. The same composite also achieved 78 % reduction of 4-nitrophenol without any external reducing agent. Furthermore, adsorption isotherms models and statistical analysis were applied to the composite to elucidate the adsorption mechanism and the optimal conditions. The results demonstrated that the composite is an excellent candidate for environmental remediation due to its remarkable degradation and adsorption capabilities against organic pollutants.

Photocatalytic removal of rhodamine B using a novel g–C3N4–organic solid waste biochar composite: Pathway, key factors, and mechanism

Over the past decades, water pollution caused by organic dyes has attracted extensive attention. The development of efficient, environmental friendly photocatalysts is a promising route for wastewater purification. Herein, a novel wild jujube shell derived biochar/g-C3N4 (BC/CN) composite has been prepared via a one-step calcination route. Although the specific surface area (9.37 m2/g) and pore size (14.57) of the BC/CN composite are smaller than those of g-C3N4, it exhibits enhanced photocatalytic activity. Especially, the 0.25-BC/CN composite (sour jujube shell powder/melamine ratio = 0.25) displays excellent photocatalytic activity, and can degrade ∼97.1 % of RhB under 40 min light irradiation, which is ∼46.51 times to that of pure g-C3N4. The actives species of h+, ·OH, ·O2− and 1O2 active species play the important roles in the photocatalytic system of the BC/CN composite. The results mechanistic study demonstrates that the enhanced photocatalytic activity of the BC/CN composite can be mainly attributed to the improved light absorption and charge separation efficiency of the catalyst. This work provides a simple method for preparing of novel highly efficient g–C3N4–based photocatalyts for wastewater purification, and provides a new idea for the recycling, and high-value utilization of the organic solid waste from traditional Chinese medicine.

Metal-Free Carbon Co-Catalysts for Up-Conversion Photo-Induced Catalytic Cancer Therapy.

Near-infrared (NIR)-responsive metal-free carbon co-catalysts that convert glucose into H2O2 to generate reactive oxygen species (ROS) are developed from phosphorus-doped carbon nitride (P-C3N4) and graphene quantum dots (GQD) composites, for enhanced photocatalytic cancer therapy by light exposure in the targeted tumor microenvironment. Upon irradiation, the NIR light is converted by GQD with up-conversion function into visible light to excite P-C3N4 for photocatalytic conversion of glucose into H2O2, which subsequently decomposes into ROS. ROS thus generated exhibits an excellent anticancer efficacy for efficient cancer therapy with minimal side effects, as evidenced by both in vitro and in vivo studies. This study demonstrates, for the first time, a cancer therapeutic of GQD/P-C3N4 composite that utilizes a two-step cascade effect using initially NIR-triggered GQD nanoparticles to activate P-C3N4 to photocatalytically generate ROS for effective and targeted cancer therapy.

Construction of NiTiO3/g-C3N4 heterojunction with preferable photocatalytic performance for tetracycline degradation

Tetracycline antibiotics as one of the most widely used antibiotics at present, are difficult to degrade in the environment, which poses a serious threat to the ecosystem and human health. In this work, NiTiO3/g-C3N4 composites were successfully constructed by calcination method using nickel acetate tetrahydrate as nickel source and tetrabutyl titanate as titanium source. The photocatalytic degradation efficiency of the 5 wt% NiTiO3/g-C3N4 composite of TC can reach 88.2 % within 150 min, which was 1.4 and 2.2 times higher than that of pure g-C3N4 (63 %) and NiTiO3 (40 %), respectively. The 5 wt% NiTiO3/g-C3N4 composite can still maintain good stability after four cycles. The experimental results showed that the construction of Z-scheme heterojunction can effectively improve the photocatalytic activity of the catalysts and maintain good redox properties at the same time. Furthermore, a possible mechanism of photocatalytic degradation of NiTiO3/g-C3N4 heterojunction has been suggested.

Construction of Ag3PO4/g-C3N4 Z-Scheme Heterojunction Composites with Visible Light Response for Enhanced Photocatalytic Degradation.

Ag3PO4/g-C3N4 photocatalytic composites were synthesized via calcination and hydrothermal synthesis for the degradation of rhodamine B (RhB) in wastewater, and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The degradation of RhB by Ag3PO4/g-C3N4 composites was investigated to evaluate their photocatalytic performance and cyclic degradation stability. The experimental results showed that the composites demonstrated notable photocatalytic activity and stability during degradation. Their high degradation efficiency is attributed to the Z-scheme transfer mechanism, in which the electrons in the Ag3PO4 conduction band and the holes in the g-C3N4 valence band are annihilated by heterojunction recombination, which greatly limits the recombination of photogenerated electrons and holes in the catalyst and enhances the activity of the composite photocatalyst. In addition, measurements of photocurrent (PC) and electrochemical impedance spectroscopy (EIS) confirmed that the efficient charge separation of photo-generated charges stemmed from strong interactions at the close contact interface. Finally, the mechanism for catalytic enhancement in the composite photocatalysts was proposed based on hole and radical trapping experiments, electron paramagnetic resonance (EPR) analysis, and work function evaluation.

Enhanced PMMA Denture Bases Using Functionalized MWCNT Fused g-C3N4 Nanocomposites

This study presents the development and analysis of a new metal-free nanocomposite that incorporates functionalized multi-walled carbon nanotubes (f-MWCNTs) with graphitic carbon nitride (g-C3N4) for reinforcing polymethyl methacrylate (PMMA) denture bases. The f-MWCNTs were integrated with g-C3N4 nanoparticles, and their structural and morphological features were examined using various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy. A mechanical blending process was employed to synthesize the nanocomposite by mixing 2 wt% of the f-MWCNT/g-C3N4 with PMMA polymer powder, followed by heat curing to form the composite material. Specimens for mechanical testing were crafted to measure flexural strength, impact resistance, compressive performance, and hardness. The findings revealed that the f-MWCNT/g-C3N4-reinforced PMMA composites outperformed standard PMMA in mechanical robustness. Surface examination of the tested samples through SEM showed distinctive dimpling and roughness, indicating a toughened fracture surface in comparison to pure PMMA and g-C3N4 samples. The study concludes that this innovative f-MWCNT/g-C3N4 composite is a promising reinforcement for PMMA denture bases, enhancing both their mechanical and physical attributes.Keywords: PMMA, functionalization, MWCNTs, Graphitic Carbide Nitride, Mechanical Properties and Denture Base

Novel 2D layered g-C3N4 nanocomposite materials for sustainable wastewater treatment by catalytic degradation of toxic dye

The photocatalytic degradation technique is one of the suitable ways of dealing with environmental pollutant decontamination. This study demonstrates the ability of graphitic carbon nitride (g-C3N4) nanocomposites containing tellurium (Te) and molybdenum disulfide (MoS2) to photocatalytically destroy organic cationic methylene blue (MB) dye, which is primarily used in the textile industry. Using the alkali treatment approach, layered graphitic carbon nitride (g-C3N4) was created. Using MoS2 and Te, several g-C3N4 nanocomposites were created using ultrasonic calcination techniques. After the MoS2 and Te were immobilized individually, the composites underwent a methodical characterization process utilizing a variety of instruments, including XRD and SEM. Using a 2D layered nano-g-C3N4 substrate, the photo-catalytic degradation reaction of MB was observed, and a UV spectrophotometer was used to determine the absorbance of the MB dye. Using 0.2 % MoS2/g-C3N4 and 5 % Te/g-C3N4, the photocatalytic degradation efficiency of the MB dye (10, 15, and 20 mg/L) solution was examined. In comparison to other produced nanocomposites, the 5 % Te/g-C3N4 composite was shown to have the highest photocatalytic activity in terms of dye degradation ability, and about 100 % of the MB dyes were degraded in less than 60 minutes. As the concentration of MB increased, the dye degradation efficiency of g-C3N4 nanocomposites steadily dropped, and the degradation rate of MB was around 1.5 mg/L.

Vanadium doped nickel oxide/g-C3N4 composites for multifunctional biosensing of dopamine, ascorbic acid and H2O2

We demonstrated a nonenzymatic electrochemical sensor based upon vanadium-doped nickel oxide composite with graphitic carbon nitride. The g-C3N4 was prepared by annealing Urea at 550 °C for 3 h in a muffle furnace. The nanocomposite was synthesized using a microwave-assisted method, followed by thermal annealing at different temperatures. The successful formation of V–NiO/g-C3N4 was confirmed by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. SEM images show the layered sheets with porous structure, which depends on annealing temperature; as we increase the temperature, the porosity increases. Afterwards, the electrochemical sensing properties were verified by CV, LSV, DPV, and amperometric studies in 0.2 M KOH in the presence of Ascorbic acid and Dopamine. The experimental results show that our prepared sample has excellent electrochemical biosensing abilities towards AA and DA with LOD 1.16 μM and 0.16 μM, respectively. It also offers good selectivity, exceptional reproducibility, and long-term stability owing to the combined effect of NiO and g-C3N4. Finally, the electrochemical sensing of H2O2 was detected in the same environment by conducting CV and amperometric studies. Our modified electrode has proven its noble ability to sense H2O2 with excellent repeatability, stability and low LOD 0.2 μM with a wide linear working range (0.5 mM–4 mM). It has the potential to be used for multi-molecule selection biosensing with excellent selectivity and sensitivity.

Comprehensive Study on the Properties of AZ91/x-Si3N4 Composites for Their Prospective Application

Metal alloy matrix composites are generally lightweight structural materials with a high strength-to-weight ratio. They can be extensively used in various fields of modern engineering applications, such as aerospace and automotive components and biomedical engineering. This study focuses on the development and characterization of lightweight metal alloy matrix composites for industrial applications, with a particular emphasis on magnesium (Mg) alloys as a replacement for aluminum-based alloys. Mg alloys offer significant weight advantages, being 33% lighter than aluminum and 75% lighter than steel, making them highly desirable for use in various engineering fields. In the present study, Mg (AZ91) alloy reinforced with x-Si3N4 composites (x = 0, 1, 3, 5, 7, 9 wt.%) were fabricated using a liquid state process. The AZ91/x-Si3N4 composites were evaluated through physical, mechanical, wear, and microstructural characterization. The experimental results, supported by statistical analysis, demonstrated that the incorporation of Si3N4 particles amplified the mechanical properties, wear resistance, and porosity of the composites. However, the presence of the reinforced particles resulted in reduced forgeability and elongation, limiting certain deformation characteristics. The existence of the reinforced particles within the composites was confirmed through SEM analysis, providing visual evidence of their distribution and interaction within the Mg alloy matrix. Finally, it was concluded that the implication of the study could be sought for the light structural parts of aerospace, automotive, biomedical, and prosthetic applications.

Simultaneously Utilizing Excited Holes and Electrons for Piezoelectric-Enhanced Photoproduction of H2O2 from S-Scheme 2D S-Doped VOx/g-C3N4 Nanostructures.

2D/2D step-scheme (S-scheme) piezo-photocatalysts for the production of fine chemicals, such as hydrogen peroxide (H2O2), have attracted significant attention of global scientists owing to the efficiency in utilizing surface piezoelectric effects from 2D materials to overcome rapid charge recombination in photocatalytic processes. In this research, we reported the fabrication of 2D S-doped VOx deposited on 2D g-C3N4 to produce H2O2 via the piezo-photocatalytic process with high production yields at 20.19 mmol g-1 h-1, which was 1.75 and 4.87 times higher than that from solely piezo-catalytic and photocatalytic H2O2 generation. The finding pointed out that adding sulfur (S) to VOx can help to improve the catalytic outcomes by modifying the electronic properties of pristine VOx. In addition, when coupled with g-C3N4, the presence of S limits the formation of graphene in the VOx/g-C3N4 composites, causing shielding effects and pushing the cascade reactions toward water generation in the materials. Besides, the research also sheds light on the charge transport between g-C3N4 and S-VOx under irradiation and how the composites work to trigger the formation of H2O2. The presence of S in the composite systems enhances charge transfer between two semiconductors by strengthening the internal electric fields (IEF) to drive electrons moving in one direction, as demonstrated by density functional theory (DFT) calculations. Moreover, the formation of H2O2 significantly relies on the reduction of oxygen to generate oxygenic radical species at the g-C3N4 sites. Meanwhile, S-VOx provides oxidative sites in the composites to oxidize water molecules to directly or indirectly generate H2O2 or O2, which will further participate in the reactions to produce the final products. This study confirms the validation of S-scheme piezo-photocatalysts, thus encouraging further research on developing heterojunction materials with high catalytic efficiency, which can be used in practical conditions.

Synthesis of nanosheet-like α-Ni(OH)2/g-C3N4 hybrid anode material with enhanced lithium storage performance

Nickel hydroxide (Ni(OH)2) has been recognized as a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity, cost-effectiveness, and simple synthesis method. However, the application of Ni(OH)2 is hampered by its volume effect and poor electrical conductivity. To address these challenges, herein, a α-Ni(OH)2/g-C3N4 composite is prepared by a hydrothermal approach. The composite possesses a hierarchical nanosheet-like morphology with fibrous nanostructures on the surface. Due to the unique hybrid nanostructure and the synergistic effect of α-Ni(OH)2 and g-C3N4 components, the α-Ni(OH)2/g-C3N4 composite exhibits significantly enhanced lithium storage performance in terms of electrochemical activity, cyclability, and kinetics than the bare α-Ni(OH)2 counterpart. Specifically, the α-Ni(OH)2/g-C3N4 achieves a remarkable capacity of 696 mA h g−1 after 400 cycles at 0.5 A g−1, far larger than the corresponding value (96 mA h g−1) of pure α-Ni(OH)2. CV and GITT analysis demonstrate the α-Ni(OH)2/g-C3N4 composite has an obvious pseudocapacitance behavior and a much smaller polarization effect than the bare α-Ni(OH)2 during cycling. This work could provide clues for the structural design and performance improvement of nickel hydroxide-based anode materials for LIBs.

Extremely interfacial bonding and photocatalytic environmental remediation on amouphous-TiO2/g-C3N4 heterojunctions by mechanochemical synthesis

TiO2/g-C3N4 composites have emerged as the most potent alternative for green photocatalysis, but are plagued by low photoactivity due to poor interfacial bonding. Herein, we report a straightforward mechanical ball milling method to fabricate an amorphous TiO2/g-C3N4 heterojunction. EPR, XPS and XAFS are used to prove that the N atoms of g-C3N4 was successfully doped into the crystal lattice of Am-TiO2 and formed typical Ti···N structure. The obtained 30-AT/CN (30 wt% g-C3N4) composites can form more heterojunction interfacial bonds and extremely improve the separation of charge carriers, showing superior photocatalytic reduction performance of perrhenate (non-radioactive chemical substitute for pertechnetate) and higher photochemical degradation rate of rhodamine B than the bulk counterpart. The material has a progressive Z-scheme heterojunction (S-scheme heterojunction), which increases the transfer ability and prolongs the lifetime of the photogenerated charge carriers. These results suggest a wide range of applications in the preparation method of heterojunction photocatalysts that are potential candidates for environmental remediation.

Development of 2D/2D h-MoO3/Ag/g-C3N4 heterojunction photocatalyst with enhanced photocatalytic performance for the detoxification of methylene blue and tetracycline under solar light illumination

In this study, direct thermal polycondensation, hydrothermal, and ultrasonic techniques were used to fabricate photocatalysts consisting of bare g-C3N4 (GCN), h-MoO3 (MoO3), MoO3/g-C3N4 (MGCN), and MoO3/Ag/g-C3N4 (MAGCN) composites. These methods were used to improve the photocatalytic effect, especially for environmental applications. The surface and chemical properties of the fabricated samples were investigated by XRD, FT-IR, FE-SEM, HR-TEM, UV-DRS, XPS, and PL analysis. Bare and composite photocatalysts were tested for photodegradation of the methylene blue (MB) dye and tetracycline (TC) antibiotic under solar irradiation. The MAGCN composite material exhibits remarkable efficiency in degrading 99% of MB dye and 90% of TC antibiotic within a time frame of 60 min when exposed to sunlight irradiation. The degradation rate constants (k) of MB and TC in the most active MAGCN photocatalyst were 11.02 and 7.03 times higher than those of pristine GCN, respectively. The scavenger reaction shows that the most important reactive species in the photocatalytic process are superoxide and photogenerated holes. The outstanding photocatalytic efficiency of the MAGCN catalyst was demonstrated by the fact that Ag nanoparticles act as mediators of fast charge transfer, resulting in higher absorption of sunlight, enhanced charge separation/transfer, and regeneration by MoO3 and GCN. The MAGCN photocatalyst exhibits remarkable activity, maintains its performance over six consecutive reaction cycles, and exhibits excellent stability and reusability. Intermediates were analyzed by GC-MS, and suitable degradation pathways were proposed. These results enable the development of an effective Z-scheme heterojunction photocatalyst and facilitate its wide application in the degradation of organic pollutants in wastewater.