g-C3N4 Composites Research Articles

Ultra-high capacity and anti-interference for Cr(VI) removal by tannin-polyvinylimine modified graphite carbon nitride

To combat the increasingly serious water pollution caused by heavy metal ions, the development of efficient adsorbents is of great significance. In this study, a novel composite adsorbent for Cr(VI) removal was smartly designed using environmentally friendly materials such as tannic acid (TA) and polyethyleneimine (PEI) for surface modification of g-C3N4 nanosheets through covalent assembly of polyphenols and amines. The obtained (PEI-TA)-g-C3N4 composite was capable of efficiently and quickly adsorbing Cr(VI) in water, with a maximum adsorption capacity of 769.23 mg/g at 308 K (35 °C), which was much higher than most reported Cr(VI) adsorbents. Notably, (PEI-TA)-g-C3N4 could reduce highly toxic Cr(VI) to low toxic Cr(III) and effectively adsorb it. The Cr(VI) adsorption process was a spontaneous thermal adsorption process that conformed to the pseudo-second-order kinetic model and Langmuir isotherm model. In addition, the excellent photothermal performance of (PEI-TA)-g-C3N4 further accelerated the adsorption of Cr(VI). Moreover, the strong anti-interference ability of (PEI-TA)-g-C3N4 composite against anions and other metal ions enabled it to effectively remove Cr(VI) in complex environments, expanding its practical application scenarios. The polymer coatings rich in phenolic hydroxyl- and amine-rich formed on the large surface area of g-C3N4 and the protonation of the amino groups are the keys for (PEI-TA)-g-C3N4 composite to have ultra-high adsorption performance and strong anti-interference ability towards Cr(VI). The designed strategy of this metal-free and environmentally friendly composite with ultra-high removal of Cr(VI) capability from wastewater provides new ideas for developing green, inexpensive, and efficient adsorbents.

Facile fabrication of 3D-α-Fe2O3@2D-g-C3N4 heterojunction composite materials: Effect of iron oxide loading on the electrochemical performance

Designing heterojunction nanocomposites is crucial for optimizing supercapacitor electrodes. This study addresses the challenge by introducing a facile synthesis method for creating 3D-α-Fe2O3@2D-g-C3N4 heterojunctions through a bulk carbon nitride-assisted hydrothermal process. During this process, the growth of ferric oxide particles coincides with the exfoliation and deposition of carbon nitride, leading to simultaneous structural changes in both iron oxide and carbon nitride phases. The resulting composite's properties strongly correlate with the iron oxide loading. Comprehensive characterization using XRD, FTIR, SEM-EDAX, XPS and TEM identified three distinct structures for α-Fe2O3/g-C3N4 composites based on iron oxide loading: low, medium, and high. The medium-loaded sample demonstrated superior electrochemical performance, attributed to better interfacial contact and the formation of 3D-Fe2O3@2D-g-C3N4 heterojunctions. This composite, with an optimized 22 wt% iron oxide loading, exhibited a maximum specific capacitance of 925.1 Fg−1 at 5 mVs−1 and 498.6 Fg−1 at 6 Ag−1 in charge-discharge analysis, with stable performance over 2000 cycles. Overall, this research presents an enhanced hydrothermal method for facile preparation of effective α-Fe2O3/g-C3N4 heterojunction materials.

Efficient photodegradation of antibiotics by g-C3N4 and 3D flower-like Bi2WO6 perovskite structure: Insights into the preparation, evaluation, and potential mechanism

Antibiotics are emerging organic pollutants that have attracted huge attention owing to their abundant use and associated ecological threats. The aim of this study is to develop and use photocatalysts to degrade antibiotics, including tetracycline (TC), ciprofloxacin (CIP), and amoxicillin (AMOX). Therefore, a novel Z-scheme heterojunction composite of g-C3N4 (gCN) and 3D flower-like Bi2WO6 (BW) perovskite structure was designed and developed, namely Bi2WO6/g-C3N4 (BW/gCN), which can degrade low-concentration of antibiotics in aquatic environments under visible light. According to the Density Functional Theory (DFT) calculation and the characterization results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FITR), Scanning electron microscopy - energy spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), this heterojunction was formed in the recombination process. Furthermore, the results of 15 wt%-BW/gCN photocatalytic experiments showed that the photodegradation rates (Rp) of TC, CIP, and AMOX were 92.4%, 90.1% and 82.3%, respectively, with good stability in three-cycle photocatalytic experiments. Finally, the quenching experiment of free radicals showed that the holes (h+) and superoxide radicals (·O2−) play a more important role than the hydroxyl radicals (·OH) in photocatalysis. In addition, a possible antibiotic degradation pathway was hypothesized on the basis of High performance liquid chromatography (HPLC) analysis. In general, we have developed an effective catalyst for photocatalytic degradation of antibiotic pollutants and analyzed its photocatalytic degradation mechanism, which provides new ideas for follow-up research and expands its application in the field of antibiotic composite pollution prevention and control.

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.

Degradation of Methyl Red (MR) dye via fabricated Y2O3–MgO/g-C3N4 nanostructures: Modification of band gap and photocatalysis under visible light

In this study, graphitic carbon nitride (g-C3N4) composites with metal oxide nanoparticles (Y2O3, MgO) and their combination (CN, YCN, MCN and YMCN) were synthesized by an ultrasonic technique and were then characterized by different tools such as UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and X-ray photoelectron spectroscopy (XPS). From the XRD diffractograms of the YMCN ternary composite, the g-C3N4, cubic MgO and Y2O3 structural phases were identified. The morphology of the as prepared nanostructure from the SEM analysis revealed the dispersion of the metal oxides nanoparticles with the graphitic sheets and the presence of the corresponding elements were confirmed by the EDX and XPS data. The FT–IR bands confirmed the bonding of the metal oxides to the nitride host as indicated by the characteristic modes. A reduction of the band gap energies was confirmed by the UV–Vis to indicate its visible light possible photoactivity. Accordingly, its visible light driven photocatalytic performance was assessed for methyl red degradation. The degradation competence was highest for the ternary composite YMCN due to the coupling of the semiconductors which increases the absorption and the charge carriers’ separation as well. The kinetics of degradation was best described by pseudo-first-order, and the most active species were the holes and the hydroxyl radicals. Thus, the YMCN nanocomposite is a visible light-active photocatalyst which can be engaged in the degradation of organic pollutants.

Construction of charge transfer channels inside h-BN/ g-C3N4 composites to enhance photocatalytic activity

Water resources are an indispensable part of life, but the current water pollution problem is facing serious challenges. In this article, two-dimensional g-C3N4 and h-BN used as raw materials, a series of h-BN/g-C3N4 (BCN) composite catalysts with varying mass by designed and synthesized using combination of simple solvent volatilization and high-temperature thermal polymerization method. The degradation rate of the BCN-2 catalyst was impressively 13.7 times higher than that of the bulk g-C3N4 when RhB was used as the target pollutants, demonstrating significantly enhanced photocatalytic performance compared to both bulk g-C3N4 and h-BN. The burst experiments on free radicals revealed that h+ and ∙O2− played a predominant role in the photocatalytic system. Moreover, the introduction of h-BN into g-C3N4 nanosheets modulated their microstructure, facilitating effectively hole migration channels and enhancing synergistically the separation efficiency of photogenerated electron-hole pairs. Consequently, the composites of h-BN/g-C3N4 with remarkably enhanced photocatalytic activity were obtained.

Carbon-supported g-C3N4 photocatalyst for the treatment of vapor isobutanol as odorous VOC

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst active under visible light but exhibits low photocatalytic activity due to its low specific surface area and fast recombination rates. However, it is possible to enhance its effectiveness and performance can be significantly improved by preparing composites of g-C3N4 with activated carbon (AC). In this manuscript, agave bagasse was employed as a precursor for activated carbon ranging from relatively low, medium and high porosity. The ability of the g-C3N4/activated carbon composite to degrade isobutanol as a model odorous VOC was evaluated under visible light. Different activation/deactivation phenomena were observed at different operation times. It was found that materials with higher porosity presented a higher level of degradation of the model VOC. However, synergy between the materials was demonstrated for the dynamic removal of isobutanol. These results demonstrate the synthesis of a composite with photocatalytic and adsorption properties based on g-C3N4 supported on activated carbon obtained from agave bagasse, which could contribute to the development of green photocatalytic materials and serve as an alternative for managing waste from the tequila industry.

Puissant synergistic effect between g-C3N4 and MIL-100(Fe) for highly stable enhanced activation of H2O2 to degrade antibiotic tetracycline hydrochloride

The release of antibiotics in the environment has raised concerns about ecological damage and human health. As a promising technology, Fenton-like processes have been extensively studied to degrade pollutants in water and achieve rapid and efficient removal. Composites of metal-organic frameworks (MOFs) and graphitic carbon nitride (g-C3N4) have shown excellent performance in Fenton-like processes as a potent combination. However, there is a lack of similar studies to confirm their outstanding catalytic performance and stability in catalyzing the H2O2 process. Therefore, to complete the research in this field and to explore the efficient removal of antibiotics, composites of g-C3N4 and MIL-100(Fe) (CNMIL-x) were fabricated by post-synthesis for highly efficient H2O2 activation to remove tetracycline hydrochloride (TC-HCl). Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) show that the characteristic morphology and peaks of g-C3N4 and MIL-100(Fe) varied according to the mass ratio between them. According to X-ray photoelectron spectroscopy (XPS), Fe is primarily in the Fe(Ⅲ) state. Besides, CNMIL-1.5 shows a SBET value of 598.46 m2·g−1, a Vpore of 0.42 cm3·g−1, and a pore size of 7.31 nm, which are significantly enhanced compared with g-C3N4. During TC-HCl degradation, the degradation rate of CNMIL-1.5 (0.02772 min−1) is 9.1 and 1.8 times faster compared to that of g-C3N4 and MIL-100(Fe), respectively. Furthermore, the excellent stability of CNMIL-1.5 are demonstrated by the quintuple cyclic experiments and characterization. A possible degradation mechanism dominated by •OH as well as a relative pathway of TC-HCl removal are proposed.

Sago-shaped embedded Nanolayers of WO3/NiO/gC3N4 Nanohybrids for natural degradation of environmental pollutants: A photocatalytic sunlight mediated approach

In recent years the applicability of semiconductor nanomaterials is almost in every field of science and technology. In the current study, hybrid nanomaterials containing tungsten trioxide (WO3) and nickel oxide (NiO) supported on graphitic carbon nitride (gC3N4) were prepared by a simple hydrothermal technique. Synthesis was sequential requiring the individual preparation of gC3N4 and WO3 as preliminary. The desired composition of gC3N4, WO3, nickel nitrate, and a base was transferred to an autoclave and maintained at 180°C for 18 h. The resulting inorganic/organic hybrid was filtered, washed, dried, and named as inorganic/organic hybrid nanocomposite (HNC). Various compositions of HNC were prepared and characterized by Fourier transform infrared spectrometer (FT-IR), Ultra Violet-Visible Diffuse reflectance spectrometer (UV–Vis-DRS), X-ray diffractometer (XRD), and Field emission scanning electron microscope (FE-SEM). The FE-SEM images showed a sago-shaped embedded particle in gC3N4 layers with a 40–60 nm particle size. The band gap energy was found to be 2.69 eV from UV–Vis-DRS analysis. This proves the promising activity of sago-shaped HNC under sunlight radiation. Various preliminary and kinetic studies were conducted, and HNC possessed excellent photocatalytic activity for the degradation of an organic dye under sunlight. The photocatalytic activity for the degradation of dye by the prepared HNC was found to be two-fold when compared to the activity of pristine gC3N4 under sunlight irradiation.

Synthesis of g-C<sub>3</sub>N<sub>4</sub>/biochar materials for photocatalytic degradation of doxycycline in aqueous solution under visible light irradiation

This study used reed biomass and urea as raw materials to produce biochar and g-C3N4 by pyrolysis under N2 atmospheric conditions at 400oC and 520oC, respectively. The g-C3N4/biochar materials were prepared by dispersing different masses of g-C3N4 onto the biochar surface and characterized by XRD, SEM, BET, FT-IR and UV-Vis-DRS methods. The photocatalytic degradation on doxycycline (DC) was investigated from the factors of pH and concentration. The characterization showed that g-C3N4 was well incorporated on the surface of biochar and increased the specific surface area of the material. The presence of biochar narrowed the band gap and increased light absorption at a wider wavelength range of g-C3N4. The composite of g-C3N4/biochar ratio of 2/1 presented the best performance, which is 2.38 times faster than g-C3N4 degrading DC. Kinetic studies showed that DC degradation followed pseudo-first-order kinetics with a determined rate constant kapp = 4,82×10-2 min−1 at a concentration of 5.0 mg/L DC. The study shows that the g-C3N4/biochar material has great potential in the treatment of antibiotic contaminated wastewater.

Embedded iron and nitrogen co-doped carbon quantum dots within g-C3N4 as an exceptional PMS photocatalytic activator for sulfamethoxazole degradation: The key role of Fe[sbnd]N bridge

The covalent modification of graphite-phase carbon nitride (g-C3N4) by carbon quantum dots (CQDs) is a promising way to improve its photocatalytic performance. Although CQDs can act as charge mediator for electrons storage and transfer, it is crucial to construct efficient interfaces, which serves as active sites for tight connect with g-C3N4 and fast release of electrons. Herein, a novel iron and nitrogen co-doped carbon quantum dots (Fe, N-CQDs) assembled g-C3N4 composite (FNCCN) was constructed via FeN bridge by hydrothermal and thermal polymerization methods. The FNCNN rivaled popular nitrogen-doped carbon quantum dots (N-CQDs) combined with g-C3N4 composites for peroxymonosulfate (PMS) activation and degradation of sulfamethoxazole (SMX). The SMX degradation rate (0.0963 min−1) is 5.38 and 3.15 times higher than that of g-C3N4 and N-CQDs/g-C3N4. The characterization and DFT calculation results suggest that Fe, N-CQDs was successfully incorporated into carbon matrix of g-C3N4 via FeN covalent bond, which joints the two counterparts closely and creates electron transport channels for higher electrons transfer efficiency. The FeN coordinated structure promotes PMS reduction on Fe2+ of FeN sites for HO and SO4- production and expedited photo carries separation through Fe3+/Fe2+ cycling. In addition, the degradation efficiency, ROS identification, EPR test and degradation pathway of SMX was determined, and the intermediate toxicity of degradation products was predicted. This work constructed a tight atomic-level connection between hydrophobic g-C3N4 and hydrophilic CQDs, which improved an effective strategy for accelerating electron transport and efficient photocatalytic activation of PMS.

The influence of morphological changes on the physicochemical and optical properties of g-C3N4

As a semiconductor material, g-C3N4 has attracted attention with proficient charge storage and transfer characteristics. However, there is a limitation in its applications because of the low specific surface area and the small number of active sites associated with the bulk structure, and there is a lack of in-depth understanding of its optical properties. In this paper, we have discussed four different morphologies of g-C3N4, including bulk (B–CN), hexagonal hollow tubular (T-CN), alveolate (A-CN), and hollow spherical (S–CN) that have been prepared using the supramolecular self-assembly strategy. To examine the changes in morphology that affect the physiochemical and optical properties of the g-C3N4. With the change in the ratio of the raw materials and reaction condition, the number of defects in g-C3N4 represented by uncondensed NH2/-NH groups changes, thus inhibiting the recombination of photogenerated carriers. Meanwhile, the changes in morphology affect the microstructural composition of g-C3N4, which changes the energy band positions and fluorescence properties of the material. This work provides some valuable information on the morphological regulation of g-C3N4 and how to modulate the morphology to change the properties of g-C3N4.

Ag/α-Fe2O3/g-C3N4 nanocomposites as Z-scheme heterojunction photocatalysts for degradation of RhB

In this study, Ag/α-Fe2O3/g-C3N4 composites with varying α-Fe2O3 and Ag contents were synthesized by loading α-Fe2O3 and Ag nanoparticles onto the g-C3N4 with a high specific surface area via acid annealing. These composites were then utilized for the photocatalytic degradation of RhB under the irradiation of visible light. For α-Fe2O3/g-C3N4 composites with 5 wt% content of α-Fe2O3, the degradation efficiency reached a peak of 97.57% within 55 min, which was much higher than that of α-Fe2O3 and acid-annealed g-C3N4 with 45.92% and 83.61%, respectively. Furthermore, the photocatalytic degradation efficiency of Ag/α-Fe2O3/g-C3N4 composites reached its maximum of 99.61% with 1% content of Ag. It was demonstrated that the ternary Z-scheme heterojunction construction leaded to a significant enhancement of carrier separation and transfer effects, while the incorporation of Ag serves as electron reservoirs and photoinduced electrons capturers, thereby significantly enhancing the Fenton reaction and photocatalytic performance. This work is significant to drive the widespread application of g-C3N4 based heterojunctions in photocatalytic water purification.

Investigation of structural, linear, and nonlinear optical properties of nanosized zinc oxide and cadmium oxide particles ingrained in graphitic carbon nitrides

The study aims to evaluate the third-order optical nonlinearity caused by laser irradiation in transition metal oxide incorporated into graphitic carbon nitrides. The work describes the synthesis of nano-sized hybrid g-C3N4/ZnO (14%) and g-C3N4/CdO (14%). Nano-sized transition metal oxides: ZnO and CdO, have been prepared by thermally decomposing the organic precursors; Zinc Acetate Dihydrate, Cadmium Acetate Dihydrate, and Urea at 873 K. Graphitic carbon nitrides are synthesized from urea, which also functions as a reducing agent. The synthesized sample’s structural and morphological characterization are investigated using x-ray diffraction (XRD), Fourier transforms infrared (FTIR), UV–vis. spectra, field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDX). The grain size of the ZnO and CdO nanoparticles is observed to be ∼21 nm and ∼28 nm, respectively. The absorption in the samples is found to be 250–450 nm and transmit the light in the visible spectrum as observed in UV–vis. spectra. The bandgap values calculated from Tauc’s plot for the hybrid structure of g-C3N4/ZnO and g-C3N4/CdO are found to be 2.97 eV and 2.30 eV.The z-scan method is adopted to evaluate the nonlinear susceptibility (χ3), intensity-dependent absorption coefficient (β), and nonlinear index of refraction (n2) using a pulsed Nd:YAG laser (∼532 nm). The results of the composite of g-C3N4/ZnO and g-C3N4/CdO show good third-order susceptibility and hence are useful for use as an optical limiter.

Enhancing photocatalytic destruction of lignin via cellulose derived carbon quantum dots/g-C3N4 heterojunctions

Lignocellulosic biomass exhibits a promising potential for production of carbon materials. Nitrogen and phosphorus co-doped carbon quantum dots (N,P-CQDs) were fabricated via (NH4)2HPO4 assisted hydrothermal treatment of cellulose pulp fibers. The as-prepared N,P-CQDs were characterized by HRTEM, FTIR, fluorescence and UV–vis, and then incorporated into g-C3N4 (CN) through sonication and liquid deposition, forming N,P-CQDs/sonication treated g-C3N4 (C-SCN) composites, which were then explored as photocatalysts. The photocatalytic ability of C-SCN towards model lignin was further analyzed. The results showed that, the fluorescence intensity and photoluminescence performance of N,P-CQDs were much higher than that of CQDs; the heterojunction was successfully constructed between the composites of N,P-CQDs and SCN; the incorporation of N,P-CQDs enhanced the visible light absorption, but reduced the band gap of the composite heterojunction; the resultant photocatalysts exhibited a good photocatalytic ability of model lignin via catalyze the fracture of β–O–4′ ether bond and CC bond, i.e., the photocatalytic degradation ratio reached up to 95.5 %; and the photocatalytic reaction generated some valuable organics such as phenyl formate, benzaldehyde, and benzoic acid. This study would promote the high value-added utilization of lignocellulosic resources especially in the transformation of lignin, conforming the concept of sustainable development.

Facile fabrication of AgBr/HCCN hybrids with Z-scheme heterojunction for efficient photocatalytic hydrogen evolution

Constructing a Z-scheme heterojunction with enhanced photocatalytic hydrogen evolution for graphitic carbon nitride-based (g-C3N4) composites is challenging because integrating g-C3N4 with other semiconductors, without specific band structure design, typically results in type I or type II heterojunctions. These heterojunctions have lower redox ability and limited enhancement in photocatalysis. Herein, we select highly crystalline carbon nitride (HCCN) as a proof-of-concept substrate. For the first time, we develop a AgBr nanosphere/HCCN composite photocatalyst that features an all-solid-state direct Z-scheme heterojunction for visible-light photocatalytic hydrogen evolution. The electron transfer mechanism is initially studied from the band structures and Fermi levels of HCCN and AgBr. It is subsequently confirmed by X-ray photoelectron spectroscopy (XPS), and electron microscopy. The close heterojunction contact and the built-in electron field of the Z-scheme heterojunction promote the migration and separation of photogenerated electrons and holes in the composite photocatalyst. Due to the redistribution of charge carriers, the photocatalyst shows superior redox capability and a markedly enhanced hydrogen evolution performance compared to its individual components. Combining all the advantages, AgBr nanosphere/HCCN reached an apparent quantum efficiency (AQE) of 6 % under the illumination of 410 nm, which is 4 times higher than that of the single HCCN component.

Purification of aqueous orange II solution through adsorption and visible-light-induced photodegradation using ZnO-modified g-C3N4 composites.

Semiconductor-based remediation enables environmentally friendly methods of removing aqueous pollutants. Simply fabricated ZnO modified g-C3N4 composites were utilized as bifunctional adsorptive photocatalysts for orange II removal from aqueous solution through adsorption and photocatalysis processes. The adsorption isotherm data of the g-C3N4 (g-CN) and ZnO modified g-C3N4 (ZCN) composites on orange II solution were better fitted with the Langmuir isotherm compared to the Freundlich isotherm. The maximum adsorption capacity for ZCN-2.5 was slightly higher than that of bare g-CN. According to the adsorption thermodynamics investigation of ZCN-2.5 in orange II solution, the positive values of Gibb's free energy change (ΔG0) suggested a non-spontaneous adsorption process. Furthermore, the negative values of entropy change (ΔS) and enthalpy change (ΔH) indicated the decrement of randomness and exothermic nature during the adsorption process, respectively. The photocatalytic degradation kinetics of g-CN and ZCN composites indicated that the degradation process follows the pseudo-first-order reaction kinetic. The degradation rate of orange II with the ZCN-2.5 composite was 6.67 times higher than that obtained with bare g-CN. Possible adsorption and photocatalytic mechanisms have been proposed.

Nanostructured MnO x /g-C3N4 for photodegradation of sulfamethoxazole under visible light irradiation.

The effectiveness of g-C3N4 as photocatalyst is hindered by the rapid recombination of photo-generated electron/hole pairs. To improve its photocatalytic performance, the incorporation of g-C3N4 with co-catalysts can promote charge separation efficiency and enhance redox capabilities. In our study, a two-step approach involving calcination and solvothermal method was utilized to fabricate a proficient MnO x /g-C3N4 heterojunction photocatalyst with high photocatalytic activity. MnO x is effective at capturing holes to impede the recombination of electron/hole pairs. The MnO x /g-C3N4 composite shows a notable improvement in photocatalytic degradation of SMX, obtaining an 85% degradation rate, surpassing that of pure g-C3N4. Furthermore, the MnO x /g-C3N4 composite exhibits remarkable and enduring catalytic degradation capabilities for sulfamethoxazole (SMX), even after four consecutive reuse cycles. The intermediates produced in the MnO x /g-C3N4 system are found to be less hazardous to common aquatic creatures such as fish, daphnids, and green algae when compared to SMX. With its high tolerance, exceptional degradation ability, and minimal ecological risk, the MnO x /g-C3N4 composite emerges as a promising candidate for eliminating antibiotics from wastewater resources.

Bromoargentate/g-C3N4 heterojunction by in situ growth: 2-D bromoargentate framework with a transition metal complex linker and cocatalyst for enhanced photocatalytic activity via g-C3N4 hybrid

[{Cu(phen)}2(μ-OH)2(Ag3Br5)]n (1)/g-C3N4 composite was prepared by in situ growth under solvothermal conditions. The composite exhibited much higher photocatalytic efficiency than the parents 1 and g-C3N4 in the degradation of crystal violet.

N-doped Ti3C2-reinforced porous g-C3N4 for photocatalytic contaminants degradation and nitrogen reduction.

Herein, a series of N-doped Ti3C2/porous g-C3N4 composites are ultrasonically prepared from N-doped Ti3C2 and porous g-C3N4 under N2 atmosphere. The structure, morphology, and optical characteristics of the as-prepared composites are characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, etc. Moreover, photocatalytic measurements show that N-doped Ti3C2 is an excellent modifier for porous g-C3N4 to heighten its photocatalytic activity. Only 44.1% of rhodamine B can be degraded by the photocatalysis of pristine porous g-C3N4, while the photocatalytic degradation ratio of rhodamine B can reach up to 97.5% for the optimal N-doped Ti3C2 loading composites under visible light for 15 min. Moreover, the photocatalytic tests of N2 fixation confirm that the optimal composites show the highest production yield of NH4+ (11.8 μmol gcat-1 h-1), which is 2.11-folds more than that of porous g-C3N4 (5.6 μmol gcat-1 h-1). The reinforced photocatalytic properties are revealed to profit from the more photogenerated electrons and holes' separation, higher ability for light response, and more abundant active sites. This work develops the route for boosting the photocatalytic properties of porous g-C3N4 with N-doped Ti3C2.