g-C3N4 Materials Research Articles

Visible Light-Driven Selective Oxidative Transformation of Vicinal Diols Using ZnS-Based Photocatalyst in the Presence of Molecular Oxygen

The heterogeneous photocatalysis for the oxidative cleavage of C-C bond is significant to the transformation of biomass feedstock. In this work, a heterojunction photocatalyst based on the conductor ZnS and g-C3N4 (CN) material is prepared and employed in the aerobic oxidative cleavage reaction of vicinal diol under visible light irradiations. As a result, it is found that 3ZnS/CN catalyst obtained by a mechanical grinding method shows a high photocatalytic activity. In the photocatalytic oxidative cleavage process of 1-phenyl-1, 2-glycol, more than 98.7% conversion of substrate with a 96.2% selectivity of benzaldehyde was attained using O2 as oxidant. In addition, the photocatalyst recycling experiments exhibited that the 3ZnS/CN catalyst still kept a good activity and stability even after being recycled for 5 times. Finally, the active reaction intermediates are investigated by the control experiments and the relative EPR detection. According to the obtained results and photocatalytic principle, the mechanism for the selective oxidative transformatioin of 1-phenyl-1, 2-glycol has been proposed. It gives a promising approach for the catalytic utilization of biomass-based lignin and cellulose.

Modulating Schottky barriers and active sites of Ag-Ni bi-metallic cluster on mesoporous carbon nitride for enhanced photocatalytic hydrogen evolution

The advancement of photocatalysis relies on the development of novel hetero-structured materials with unique architectures. In this study, we successfully synthesized a hetero-structured g-C3N4 (GCN) material with a distinctive surface-interface modification. To further enhance its photocatalytic performance, we optimized the Ag and Ni concentration to maximize the visible light absorption and catalytic active sites for hydrogen evolution reactions. By using systematic physicochemical characterizations and density functional theory (DFT) calculations, we elucidated the pivotal role of graphitic carbon nitride (g-C3N4) in facilitating the formation of an efficient charge transfer channel and promoting the effective generation and separation of photo-generated carriers. From the DFT calculations, we also demonstrated that the Ag and Ni nanoparticles provide more efficient visible light absorption and active sites than Ni nanoparticles for water splitting and hydrogen evolution and In-situ TEM exploration. Furthermore, the hetero microstructure consisting of thin g-C3N4 nano scrolls has a crucial role in shortening the migration distance of the carriers, effectively suppressing carrier recombination. Consequently, these extraordinary characteristics resulted in a superior solar light-driven photocatalytic H2 evolution rate of 2507 μmol.h-1.g−1, surpassing the rate achieved by g-C3N4 heterostructures by a remarkable 18.6-folds. Moreover, the apparent quantum efficiency of this hetero-structured material reached an exceptional value of 1.6 % under a 1.5 G air mass filter.

Characterisation Analysis of Sulphur and Phosphorous Doped and Co-doped Graphitic Carbon Nitride (g-C3N4) Materials

Graphitic carbon nitride (g-C3N4) is tailored with doping of different non-metals (Sulphur and Phosphorus). For synthesis through thermal condensation method, the mixtures of urea and dopant with diverse concentrations have been added for preparation of materials. The basic effect of doping and its concentration on the structural morphology and absorption spectra of the samples is investigated in detail. Pure g-C3N4 suffers from high recombination rate of photogenerated electron-hole pairs resulting in low photocatalytic activity. Different techniques like X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectroscopy, and Photoluminescence spectroscopy (PL) have been used for the characterization. X-ray diffraction studies confirm the formation of the g-C3N4 structure and SEM images reveal crumpled sheets and irregular plate like shapes of the doped graphitic nitride samples. FTIR analysis identify the presence of surface amino (N-H) and water (O-H) groups, cyano terminal group (C≡N), (C≡C), C–N) and (C=N) bonds and breathing mode of the tri-s-triazine units in the samples. PL spectra shows that the sulphur and phosphorus co-doped PSGCN (8 wt.%) sample is better for photocatalytic activity.

Incorporation of hydroxyl groups and π-rich electron domains into g-C3N4 framework for boosted sacrificial agent-free photocatalytic H2O2 production

Photocatalytic synthesis of hydrogen peroxide (H2O2) based graphitic carbon nitride (g-C3N4) materials has garnered significant attention due to its green and sustainable attributes. In this study, g-C3N4 nanosheets enriched with π‑rich electron domains and hydroxyl groups were synthesized through the pyrolysis of urea-tartaric acid mixed solution, and subsequently utilized for efficient photocatalytic production of H2O2. The incorporation of π-rich electron domains induced a downward shift in the conduction band edge, which can significantly diminish the Coulombic interactions of singlet Frenkel excitons, thereby facilitating efficient photo-generated charge separation and accelerated charge migration. Simultaneously, the modification with hydroxyl groups in g-C3N4 network enhances water molecule adsorption, reducing side reactions and thereby increasing the efficiency of selective H2O2 generation. The integration of π-rich electron domains with hydroxyl groups in g-C3N4, along with a comprehensive understanding of their underlying mechanisms, provides valuable insights for the rational design and synthesis of highly active energy conversion catalytic materials.

Preparation of C-doped g-C3N4 by Co-polycondensation of melamine and sucrose for improved photocatalytic H2 evolution

g-C3N4, a well-known semiconductor is widely used for photocatalysis because of its renowned and special properties. It is a nonmetallic polymeric material that is abundant in sources and easy to prepare, making it an attractive choice for photocatalysis that responds to visible light. However, due to various intrinsic structural and chemical drawbacks, it is very far from further applications. Herein, we used sucrose to modify the physicochemical characteristics of ordinary g-C3N4 to prepare a carbon self-doped g-C3N4 (Cn-MA) material through co-polycondensation with melamine and applied it for hydrogen production. The characterization showed that the addition of sucrose resulted in a narrowed band gap, widened absorption range, enhanced photoresponse, and photogenerated charge carrier separation. Furthermore, the prepared material was applied for hydrogen production activity, which revealed that it has higher photocatalytic performance than pristine g-C3N4. The H2 production rate of the optimized material (C7.5-MA) was recorded as 7.3 times greater than that of pure g-C3N4. Through cycling tests, the stability of C7.5-MA was examined. The results showed that, even after four consecutive cycles, no apparent drop in its performance was observed. Additionally, here the mechanism of hydrogen production is also discussed.

Microwave synthesized g-C3N4 nanofibers with modified properties for enhanced solar light photocatalytic performance

Graphitic carbon nitride (g-C3N4) nanomaterials have been eco-friendly synthesized using microwave and compared to the materials prepared by conventional thermal and solvothermal methods. The properties of as-synthesized g-C3N4 nanomaterials were investigated by various techniques. The results demonstrated the successful synthesis of g-C3N4 either by conventional or microwave methods. However, morphology and surface area have been changed by changing the method used. While small sheets were obtained using thermal decomposition of melamine for 4 hrs. at 500 °C, and irregular particles were obtained from the solvothermal synthesis by heating melamine and cyanuric chloride for 16 hrs. at 180 °C, nanofibers structure with the largest surface area was obtained by microwave irradiation of melamine and cyanuric chloride for 1hr. The photocatalytic performance of the synthesized materials has been assessed for the decomposition of phenol and methyl orange (MO) dye. All prepared g-C3N4 materials have shown better solar light photocatalytic performance compared to TiO2 nanoparticles. This has been directly correlated to the narrower band gab energies of g-C3N4 materials (Eg(TGCN) = 2.8 eV, Eg(SGCN) = 2.4 eV, Eg(MGCN) = 2.45 eV) compared to TiO2 (3.1 eV). Moreover, the photocatalytic activity of microwave prepared g-C3N4 (MGCN) is about 2 times higher than those prepared by the other methods (TGCN & SGCN) and ∼ 7 times higher than that of TiO2. This can be readily related to the modified fibrous structure and the highest surface area of MGCN (31.84 m2/g) compared to other materials.

Melem Hydrate-Derived g-C3N4 Micro-Rods Coordinated with Cu2+: Why is Cu a superior cocatalyst compared to Ni and co?

Graphitic carbon nitride (g-C₃N₄) holds significant promise for hydrogen production due to its visible-light activity, stability, and cost-effectiveness. However, it faces challenges related to high charge recombination and trapping, which ultimately hinders its photocatalytic efficiency. In this study, we address these limitations by first modifying g-C₃N₄ nanosheets into rods through the formation of melem hydrate using an ultrasonication method. Subsequently, the melem hydrate is transformed into g-C₃N₄ micro-rods (CNR). These CNR micro-rods are further coordinated with transition metals (Ni2⁺, Co2⁺, and Cu2⁺) via a hydrothermal process. Among these samples, the Cu-coordinated micro-rods exhibit the highest photocatalytic hydrogen production rate, achieving 4 mmol/g/h. This performance surpasses previously reported novel metal-coated g-C₃N₄ materials. Notably, when compared to Ni and Co, the Cu-coordinated g-C₃N₄ produces 2.8- and 3.6-times higher hydrogen, respectively. The enhanced performance is attributed to faster interfacial charge transfer kinetics between g-C₃N₄ micro-rods and Cu, as evidenced by the highest kNT value of 0.81 ns⁻1 and kET value of 0.16 ns⁻1, measured using time-resolved photoluminescence spectroscopy.

Study on Catalytic Performance in CO2 Hydrogenation to Methanol over Au–Cu/C3N4 Catalysts

In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C3N4 material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C3N4, Au-10%Cu/C3N4, and Au-15%Cu/C3N4, catalysts were prepared and used for the catalytic reduction of CO2 to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO2, which is more beneficial for catalyzing CO2. Among them, Au-10%Cu/C3N4 exhibited good reducibility and strong basic sites, as demonstrated by H2-TPR and CO2-TPD, with the conversion rates for CO2, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg−1·h−1 (0.39 μmol·g−1s−1), and 59.77%, respectively.

Electrochemical sensing platform for anticonvulsant drug carbamazepine detection based on graphitic carbon nitride and tetrabutylammonium chloride ionic liquid

The development of a rapid and straightforward electrochemical approach for the quantification of the anticonvulsant drug carbamazepine (CBZ) is herein presented. Carbon paste electrode (CPE) was bulk modified with a type of two-dimensional conjugated polymer, i.e., graphitic carbon nitride (g-C3N4), and additionally with an ionic liquid tetrabutylammonium chloride (TBACl) to obtain advanced electrochemical sensor for CBZ. Synthesized g-C3N4 material was structurally and morphologically characterized by Raman spectroscopic, FTIR, and SEM/EDX methods. CV experiments showed that the resulting electrode (TBACl-g-C3N4-CPE) has an improved electrochemical response compared to unmodified CPE and g-C3N4-CPE due to the synergistic effect of electrode modifiers, as well as that the CBZ oxidation process is irreversible and diffusion-controlled. After optimization steps concerning the amount of electrode modifiers and the selection of pH of the supporting electrolyte, the analytical performance of TBACl-g-C3N4-CPE was investigated by direct anodic square-wave voltammetry (SWV). The most intensive peak of the target analyte was obtained in Britton-Robinson buffer solution at pH 7.0, whereby the developed SWV method was characterized by a linear concentration range of CBZ from 0.42 to 9.31 µmoL L−1, limit of detection (LOD) of 0.13 µmoL L−1, and relative standard deviation lower than 3 %. The interference study showed that TBACl-g-C3N4-CPE exhibits adequate selectivity for CBZ in the presence of ions/compounds commonly present in the urine matrix. The developed sensor was utilized to determine CBZ in pharmaceuticals and spiked human urine sample with excellent recovery and reproducibility, indicating a good application capability of TBACl-g-C3N4-CPE for monitoring CBZ in different matrices.

Co-doped C3N5 with enhanced RhB degradation by activating PMS

The application of advanced oxidation processes in wastewater treatment has attracted wide attention, in the past year. With excellent photoelectric properties and catalytic stability, graphitic carbon nitride and its derivatives have high catalytic performance. Compared to traditional g-C3N4 materials, g-C3N5 has a narrower band gap (g-C3N5 has a band gap of about 2.0 eV and g-C3N4 has a band gap of about 2.6 eV) and better electron excitation distribution due to it has a higher proportion of N atoms. In this study, the composites of Co atom doped g-C3N5 were synthesized and characterized. Co atoms are successfully doped into g-C3N5, which is proved by TEM, XPS and XRD experimental results. PMS can be activated by Co-C3N5, and RhB degradation efficiency is as high as 95.8 % within 40 min. The experimental results show that the doping of metal Co can effectively improve the catalytic performance of carbon nitride materials. The degradation efficiency of RHB activated by C3N5, C3N4 and Co-C3N4 was 18.2 %, 11.2 % and 41.8 %, respectively, while the degradation efficiency of Co-C3N5 was as high as 95.8 %. RhB was effectively degraded over a wide pH range (3.0–10.9) and under various anion conditions, indicating the excellent environmental suitability of Co-C3N5. The results of free radical quenching experiments and EPR tests showed that the contribution of active species to RhB degradation was as follows: SO4•− >1O2 > O2•−. This paper provides a new perspective using Co-C3N5 as a catalyst for PMS-based Fenton reaction.

Fabrication of ternary Bi2S3/BiVO4/g-C3N4 composite material for enhanced photocatalytic degradation of antibiotics

Antibiotic contaminants are known to pose a serious threat to the human health and environment, thus a great deal of effort has been made to develop destruction technologies for antibiotic treatment in the water environment. Photocatalytic oxidation technology is regarded as one of the most promising strategies for decomposing antibiotics from water. In this work, ternary Bi2S3/BiVO4/g-C3N4 composite material is dexterously designed and synthesized to obtain the enhanced photocatalytic performance for tetracycline (TC) degradation via a facile strategy. Therein, the optimal Bi2S3/BiVO4/g-C3N4 material showed the excellent degradation efficiency under visible light irradiation in comparison to the nude g-C3N4 and BiVO4/g-C3N4 photocatalysts, and it can continuously degrade the TC pollutant in 90 min and achieve a degradation percentage of 80.7 %. The designed materials can not only intensify photo-absorption efficiency of g-C3N4 material, but also improve its separation and transfer efficiency of photo-generated charge carriers, which is attributed to the incorporation of BiVO4 and Bi2S3 materials. The active species trapping experiments verified that the superoxide radicals (•O2−) is the main active species, and holes (h+) also played an important role in the Bi2S3/BiVO4/g-C3N4 system. Furthermore, the photoelectrochemical measurement (PEC) clearly demonstrated that the incorporation of BiVO4 and Bi2S3 materials could accelerate the separation and transfer of photo-generated electron and hole pairs. As expected, our present work could spark new inspirations to further develop the efficient photocatalysts for solar energy conversion.

Mn-Cu co-doped graphitic carbon nitride accelerates permonosulfate to generate more singlet oxygen in pollutant degradation

Graphitic carbon nitride (g-C3N4), a nitrogen-rich polymeric semiconductor, has gained significant attention as a photocatalyst. However, its potential to activate permonosulfate (PMS) has been somewhat limited. Prior research has demonstrated that manganese-doped g-C3N4 can effectively activate PMS to degrade pollutants, with Mn3+ playing a pivotal role. Consequently, enhancing the Mn3+ content within the system is of paramount importance. In this study, we developed a novel class of manganese‑copper doped g-C3N4 materials using a hydrothermal-calcination process. The optimized material, denoted as Mn5Cu5-CN, was synthesized at a Mn/Cu molar ratio of 1:1. When applied to degrade a model contaminant, acetaminophen (ACP), the Mn5Cu5-CN/PMS system demonstrated remarkable efficiency, degrading nearly 20 mg/L of ACP within 30 min (material dosage = 0.4 g/L, PMS concentration = 2.0 mM). The Mn5Cu5-CN exhibited favourable performance across a broad pH range. Singlet oxygen (1O2) was identified as a major player in the degradation of ACP. X-ray photoelectron spectroscopy (XPS) analyses revealed that the cyclic redox reactions of Mn3+/Mn4+ and Cu+/Cu2+ led to the abundant generation of 1O2. Superoxide (O2•-) was identified as an important intermediate product in these processes. Additionally, the g-C3N4 present in the material also facilitated the generation of reactive oxygen species (ROS). This study provides a fresh perspective on the utilization of g-C3N4 for pollutant degradation, highlighting the potential of MnCu doped g-C3N4 materials in environmental remediation.

Enhanced Fenton-like catalysis via interfacial regulation of g-C3N4 for efficient aromatic organic pollutant degradation

For the efficient degradation of organic pollutants with the goal of reducing the water environment pollution, we employed an alkaline hydrothermal treatment on primeval g-C3N4 to synthesize a hydroxyl-grafted g-C3N4 (CN-0.5) material, from which we engineered a novel Fenton-like catalyst, known as Cu–CN-0.5. The introduction of numerous hydroxyl functional groups allowed the CN-0.5 substrate to stably fix active copper oxide particles through surface complexation, resulting in a low Cu leaching rate during a Cu–CN-0.5 Fenton-like process. A sequence of characterization techniques and theoretical calculations uncovered that interfacial complexation induced charge redistribution on the Cu–CN-0.5 surface. Specifically, some of the π electrons in the tris-s-triazine units were transferred to the copper oxide particles along the newly formed chemical bonds (C(π)-O-Cu), forming a π-deficient area on the tris-s-triazine plane near the complexation site. In a typical Cu–CN-0.5 Fenton-like process, a stable π-π interaction was established due to the favorable positive-negative match of electrostatic potential between the aromatic pollutants and π-deficient areas, leading to a significant improvement in Cu–CN-0.5's adsorption capacity for aromatic pollutants. Furthermore, pollutants also delivered electrons to the Cu–CN-0.5 Fenton-like system via a “through-space” approach, which suppressed the futile oxidation of H2O2 in reducing the high-valent Cu2+ and significantly improved the generation efficiency of •OH with high oxidative capacity. As expected, Cu–CN-0.5 not only exhibited an efficient Fenton degradation for several typical aromatic organic pollutants, but also demonstrated both a low metal leaching rate (0.12 mg/L) and a H2O2 utilization rate exceeding 80%. The distinctive Fenton degradation mechanism substantiated the potential of the as-prepared material for effective wastewater treatment applications.

A two-symmetric electrode hydride supercapacitor developed from G-C3N4 decorated with poly-2-aminobenzenethiol

The incorporation of poly-2-aminobenzene thiol (P2ABT) onto 2D g-C3N4 sheets results in the formation of a P2ABT/g-C3N4 nanocomposite, exhibiting favorable morphological and electrical properties that position it as a promising candidate for a paste utilized in a two-symmetric electrode hydride supercapacitor. The decoration process involves the oxidation of 2-aminobenzene thiol with K2S2O8, leading to the polymer coating of the embedded 2D g-C3N4 materials, yielding a robust composite. Analysis via scanning electron microscopy (SEM) unveils the formation of 2D sheets of g-C3N4 with an average length, width, and thickness of 750 nm, 200 nm, and 15 nm, correspondingly. The composite establishes a sturdy network with a porous structure, indicative of the synergistic combination of the electrical characteristics of the polymer and g-C3N4. In the construction of the two-symmetric electrode supercapacitor, an impressive specific capacitance (CS) of 310 F g−1 is achieved at 0.2 A/g. The supercapacitor exhibits a promising energy density (E) of 26.8 W h kg−1 and maintains retention stability even after undergoing 1000 charge/discharge cycles. Notably, the retention rate remains high at 98% after 250 cycles and 96% after an extended cycling period of 1000 cycles. This exceptional performance positions the supercapacitor as a prospective candidate for applications in industrial settings and within batteries. Its advantages lie in its ease of fabrication, mass production capabilities, and cost-effective manufacturing techniques, opening new avenues for these materials in energy storage fields.

Structural, optical, and photocatalytic properties of nano-scaled g-C3N4 materials

Structural, optical, and photocatalytic properties of nano-scaled g-C3N4 materials

Design of van der Waals heterostructures composed of g-C3N4 and III-V materials for solar cell

As society develops, people pay more attention to the application of solar cell to harvest inexhaustible solar power, which has a benefit of greenness and cleanness. In this paper, we construct 14 heterostructures composed of g-C3N4 and Ⅲ-Ⅴ materials based on first-principles calculations. We systematically analyse their stability property and find a periodic rule of binding energy change about the atomic number of Ⅲ-Ⅴ material. We select 9 stable van der Waals (vdWs) heterostructures and further analyse their band alignment and power conversion efficiency (PCE). We find GaAs-D is a type-Ⅱ heterostructure with indirect band gap of 1.38 eV and the PCE reaches 15.2%. The construction of GaAs-D effectively promotes the optical absorption in visible-spectrum compared with two monolayers. This paper systematically analyses the stability of constructed vdWs heterostructures composed of g-C3N4 and Ⅲ-Ⅴ materials, electronic band structures and their potential application as solar cell.

Heterocyclic polymerization modified g-C3N4 nanotube with advanced charge separation for solar light driven degradation of ciprofloxacin

A novel heterocyclic polymerized g-C3N4 nanotube was prepared by thermal polycondensation using urea and 2,4,6-triaminopyrimidine (TAP). The TAP-polymerized g-C3N4 composite with 0.5 wt% TAP content showed the highest photocatalytic activity for ciprofloxacin (CIP) degradation under solar irradiation. The optimal composite derived from urea achieved ∼ 10.8 and ∼ 7.5 time of CIP degradation activity when compared with TAP-polymerized g-C3N4 derived from melamine and thiourea. The copolymerization of TAP molecules reduces the π electron defects in the g-C3N4 conjugated system thus accelerates the migration of photogenerated carriers. The doping of TAP in g-C3N4 reduces its band gap, which enhances the light absorption capacity and improves the utilization efficiency of visible light. The fluffy porous nanotube structure of the material endows it with unique surface morphology and excellent photoelectric characteristic. Electron spin resonance (ESR) and probe technology were used for qualitative or quantitative detection of free radicals in this work. Superoxide radicals (O2·-) played the major roles in the photodegradation of CIP. Recycling experiments displayed the high stability and activity of the modified materials, which is potentially applicable in practical engineering. Moreover, the photodegradation pathways and mechanisms of CIP were proposed and its toxicity evolution was assessed in this study. This work revealed the specific application of heterocyclic polymerization in modifying g-C3N4 material and provided unique insights for its application in photocatalytic degradation of antibiotic.

Ferroelectric-assisted enhancement of the photocatalytic activity of g-C3N4/TiO2 nanotubes heterojunctions through the addition of strontium

The effect of adding strontium to nanocomposites formed of g-C3N4/TiO2 nanotubes (TiNT) (g-C3N4: 4.0 wt%) on the photocatalytic activity was herein investigated using formic acid as a model target pollutant. g-C3N4 material was prepared by a solvothermal method using a mixture of urea and cyanuric chloride as precursors and acetonitrile as a solvent at 220 °C for 15 h, while TiNT material was obtained by the alkaline hydrothermal method of P25 at 130 °C for 20 h. A series of xSr-gC3N4/TiNT nanocomposites were then synthesized through progressive incorporation of strontium (from 0.2 to 1.0 wt%) at the surface of the composites. Samples were then characterized mainly using N2 adsorption–desorption measurements, X-ray diffraction, UV–vis diffuse reflectance, Raman and photoluminescence (PL) spectroscopies, and scanning and transmission electron microscopy (with energy-dispersive X-ray spectroscopy and Z-mapping). The Sr-containing g-C3N4/TiNT composites were then also fully characterized by electrochemical impedance spectroscopy (EIS) for their dielectric properties, while a deep kinetics analysis was also performed. Such an approach allowed us to establish a correlation between photocatalytic performance and the material's propensity to be polarized. Results emphasize the beneficial role of ferroelectricity induced by adding strontium. Indeed, enhancement of the photocatalytic activity by 2.3 times compared to a Sr-free counterpart was related to the material's ability to be polarized for Sr loadings ≤ 0.6 wt%. At higher Sr loadings, supplementary factors (decrease of the anatase crystallinity, formation of TiO2(B), disruption of the g-C3N4/TiO2 interaction, or lower mobility of photogenerated charges) negatively impact the activity, counterbalancing partly the beneficial ferroelectric effect. In this way, this study emphasizes the role played by ferroelectric effects in enhancing the photocatalytic ability of a given semiconductor.

Fabrication of spinel SrBi2O4 nanomaterials anchored on g-C3N4 nanosheets with enhanced performance of electrode material for energy storage application

Graphitic carbon nitride (g-C3N4) material with a similar structural phase to graphite opens new opportunities in energy conversion storage systems. The g-C3N4 sheets offered many defected sites that enhanced the adsorption and diffusion of electrolyte ions. High nitrogen concentration in g-C3N4 was ideal for increasing the binding energy between metals and carbon. The stability of pseudo-active metal oxides/chalcogenides supported by carbon results in improved capacitive performance. This study used a hydrothermal route to fabricate binary SrBi2O4/g-C3N4 composite onto g-C3N4 sheets. The SrBi2O4/g-C3N4 nanocomposite was characterized through various techniques including different analytical analyses. Among all evaluated electrodes for the electrochemical experiment binary composite SrBi2O4/g-C3N4 demonstrated the highest electrochemical activity and showed the capacitive of 777.2 F g−1 at 1 A g−1. Moreover, binary composite SrBi2O4/g-C3N4 was shown to have a lesser charge transfer resistance (Rct) of 0.87 Ω as compared to other bare fabricated materials. The exceptional electrochemical capability of SrBi2O4/g-C3N4 can be due to the combined effect of SrBi2O4 and g-C3N4 which included various redox state enhanced electrode wettability and superior structural and chemical stability. The composite material shows excellent power and high energy density of 319.95 W Kg−1 and 44.20 Wh Kg−1. Based on the findings our study suggested a practical approach to fabricated hybrid electrode materials that have optimum properties for use in energy storage devices in future supercapacitors.

MoB2 modified g-C3N4: A Schottky junction with enhanced interfacial redox activity and charge separation for efficient photocatalytic H2 evolution

The g-C3N4 material, which exhibits a sensitivity to visible light and has a band position that is appropriate for the photoreduction of H2, has garnered significant interest. However, the ability of g-C3N4 to use light for photocatalysis is restricted due to its insufficient capacity to absorb light and its poor reaction kinetics on the surface. The researchers opted for the metallic MoB2 to create a Schottky junction coupled with g-C3N4. The incorporation of MoB2 nanoparticles onto g-C3N4 enhances its light absorption capacity and promotes the efficient separation and transfer of photogenerated charge. In addition, MoB2 nanoparticles served as active sites to accelerate H2 evolution. Compared to g-C3N4, the MoB2@g-C3N4 composite exhibited a nearly 51-fold increase in H2 production rate, indicating a significant improvement in photocatalytic activity. The present investigation demonstrated the potential of metallic MoB2 as a modified material during a photocatalytic H2 evolution reaction.