C3N4 Composite Research Articles

The novel α-TiO2@g-C3N4 heterostructure for ultra rapid ionic pumping and effective capacitive deionization

Anatase titanium dioxide (α-TiO2) has been widely identified as an efficient electrode material for capacitive deionization (CDI). However, this material usually suffers from limited exposure of active sites, poor electrical conductivity and significant obstacles in ion movement due to its tendency to severely aggregate during its preparation. A novel approach to fabricate α-TiO2@g-C3N4 composite materials was proposed in this work. In detail, the 2D material g-C3N4 serves as a high-speed electron-conducting scaffold, allowing uniform loading of nanoscale α-TiO2 and exposing abundant active sites. Furthermore, g-C3N4 facilitates electron transport to nanoscale α-TiO2, enhancing charge transfer and activating previously underutilized electrochemical centers. As a result, α-TiO2@g-C3N4 composites were synthesized for the first time. Through these improvements, the prepared α-TiO2@g-C3N4 exhibits excellent desalination performance, with a high degree of efficiency in water purification. It shows an improved salt adsorption capacity (SAC) of 50.4 mg g-1 and a salt adsorption rate (SAR) of 2.7 mg g-1 min−1 in a 1.2 V, 1 mm electrode spacing, and 500 mg L-1 NaCl solution. This outstanding CDI performance surpasses most recently reported electrode materials. More importantly, this electrode showed remarkable removal efficiencies for various heavy metal ions (Ni2+, Cr3+, Cu2+, Pb2+, Fe3+ and Cd2+), indicating its significant potential for wastewater purification. The superior CDI performance of the α-TiO2@g-C3N4 composite material endows it with practical application in future.

Nghiên cứu tổng hợp vật liệu composite SiO2/g-C3N4 cho quá trình quang xúc tác phân hủy rhodamine B

In this study, a visible-light-driven SiO2/g–C3N4 composite was prepared by heating a mixture of SiO2 and urea. The products were characterized by X-ray diffraction (XRD), infrared spectra (IR), scanning electron microscopy (SEM), and ultraviolet–visible diffuse reflectance spectroscopy (UV-Vis DRS). Results indicate that the composite only contained SiO2 and g-C3N4, and the SiO2/g–C3N4 composite had higher photocatalytic activities in the degradation of rhodamine B (82.2%) compared to the pristine g-C3N4 (43.9%) under visible light. The SiO2/g–C3N4 composite is a promising new material for the photodegradation of organic pollutants in wastewater due to its high photocatalytic performance, low cost, and convenient collection for reuse.

Europium/Graphite Phase Carbon Nitride Composites: Preparation and Photocatalytic Degradation Potential of Different Drugs

AbstractGraphene‐like materials were prepared by thermal copolymerization using melamine as a precursor, and chemical methods successfully synthesized Eu/g‐C3N4 composites containing different europium elements. Degradation rates of 64.3 %, 91.9 %, and 72.8 % were observed in the photocatalytic degradation of Pefloxacin, Enrofloxacin, and Ciprofloxacin under visible light (λ>550 nm). Determine the photocatalytic activity of the composite. When the doping amount was Eu/g‐C3N4‐2 with k=0.0135 min−1, four times greater than that of g‐C3N4, the best photocatalytic effect was obtained. Repeated studies revealed that the Eu/g‐C3N4 composite samples had good cycle stability, and a potential degradation process was postulated.

Dual Z-scheme heterojunction Ce2Sn2O7/Ag3PO4/V@g-C3N4 for increased photocatalytic degradation of the food additive tartrazine, in the presence of persulfate: Kinetics, toxicity, and density functional theory studies

This study involved the synthesis of a Ce2Sn2O7/Ag3PO4/V@g-C3N4 composite through hydrothermal methods, followed by mechanical grinding. The resulting heterojunction exhibited improved catalytic activity under visible light by effectively separating electrons and holes (e−/h+). The degradation of Tartrazine (TTZ) reached 93.20% within 50 min by employing a ternary composite at a concentration of 10 mg L−1, along with 6 mg L−1 of PS. The highest pseudo-first-order kinetic constant (0.1273 min−1 and R2 = 0.951) was observed in this system. The dual Z-scheme heterojunction is developed by Ce2Sn2O7, Ag3PO4, and V@g-C3N4, and it may increase the visible light absorption range while also accelerating charge carrier transfer and separation between catalysts. The analysis of the vulnerability positions and degradation pathways of TTZ involved the utilization of density functional theory (DFT) and gas chromatography-mass spectrometry (GC-MS) to examine the intermediate products. Therefore, Ce2Sn2O7/Ag3PO4/V@g-C3N4 is an excellent ternary nanocomposite for the remediation of pollutants.

Photo‐catalytic Performance of MAPbI3/g‐C3N4 for Efficient Hydrogen Production under Visible Light

AbstractRecently, hydrogen (H2) production via photocatalytic process has been received enormous attention of the scientific community globally. Perovskite materials such as methyl ammonium lead iodide (MAPbI3) has excellent photovoltaic and photocatalytic properties and may be a promising photocatalyst for H2 production reaction. In this paper, we have designed and synthesized MAPbI3 perovskite embedded graphitic carbon nitride (MAPbI3@g‐C3N4) composite via benign approaches. The phase and crystalline nature was authenticated by powder X‐ray diffractometer. Morphological characteristics of the MAPbI3@g‐C3N4 composite was further checked by scanning electron microscope. The elemental composition and valence states of the MAPbI3@g‐C3N4 was determined by X‐ray photoelectron spectroscopy (XPS). Furthermore, MAPbI3@g‐C3N4 has been explored as photocatalyst for H2 production reaction using hypophosphorous acid (H3PO2) as stabilizing agent. Platinum (Pt) has been used as co‐catalyst. The reasonably good amount of H2 of 21.25 μmol/g was produced using MAPbI3 as photocatalyst. Further, improved H2 amount of 939.4 μmol/g was produced using MAPbI3@g‐C3N4. The MAPbI3@g‐C3N4 exhibited decent H2 production rate of 93.94 μmol/h/g. The excellent stability of the MAPbI3@g‐C3N4 offers its potential applications for reusable studies. This work proposed the potential application of MAPbI3@g‐C3N4 towards H2 generation applications.

Synthesis, characterization, and performance assessment of a perovskite‐type nano photocatalyst for degradation of thiamethoxam

AbstractIt is essential to remove thiamethoxam (THMX) from surface water as it negatively impacts the ecology and neurological systems of insects. Hence, a study was conducted to degrade THMX with different compositions of LaFeO3/g‐C3N4 (LFCN) composites. Several methods, including X‐ray powder diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), and field emission scanning electron microscopy (FESEM), were applied to characterize the synthesized photocatalyst. The influence of many parameters on degradation, for example, THMX concentration, dosage of catalyst, and pH were studied experimentally. The degradation was highest under both UV‐C and sunlight for the synthesized catalyst, 1% LaFeO3/g‐C3N4 (LFCN1), in comparison to graphitic carbon nitride (g‐CN), and bare lanthanum ferrite (LF). The degradation was around 95% for LFCN1 under UV‐C light having an intensity of 15 W/m2 whereas degradation was 71.8% with LFCN1 photocatalyst under sunlight at neutral pH in 120 min of reaction time. The increased activity of LFCN1 was attributable to an improved surface area and a lower band gap. The study of reaction kinetics indicated second‐order behaviour. Additionally, a probable mechanism for degradation was put forth.

Temperature response TADF/ RTP dual mode afterglow of carbon dots and flake C3N4 composites for information encryption and advanced lighting

TADF emission based on CD materials has inspired extensive attention in recent years. Herein, CD composites with afterglow color temperature-responsive were prepared by confining BCDs/ BPCDs in a g-C3N4 matrix. The covalent bonds extensively protect the triplet states and promote the ISC process, and the small △EST is sufficient to encourage the RISC process. At room temperature, the BCD composite exhibits a deep blue TADF emission, and the BPCD composite shows two TADF emission peaks in the blue-green region. BCD/ BPCD composites exhibit RTP emission at lower temperatures, and the competition between TADF and RTP leads to the color temperature-responsive properties in these composites. A simple concept of information encryption was developed to demonstrate the great potential of these composites in advanced security applications. Based on the high overall quantum yields (44 %) and broad full width at half maximum (over 140 nm) at the visible region of the BPCD composites, they are successfully applied to develop the single component fluorescence/ TADF dual-emission delay WLED with CIE coordinates and CRI of (0.32, 0.34) and 92. This work provides a new strategy for producing CDs-based TADF materials and may motivate CDs TADF materials applied in information encryption and advanced lighting application.

Anticorrosive coatings made from polydopamine modified graphitic C3N4 composites with synergistic anticorrosion effects

Since uniform dispersion and robust interfacial compatibility of nanofiller with epoxy resin are the most critical parameters to improve the corrosion protection property, a new effective anticorrosion nanofiller [polydopamine (PDA)@g-C3N4-CeO2] is designed by stacking PDA modified g-C3N4 and nano-CeO2 with the help of a silane coupling agent. The structure and morphology of PDA@g-C3N4-CeO2 are characterized by FTIR, XRD, XPS, SEM, and TEM. Furthermore, the PDA@g-C3N4-CeO2 nanofiller is loaded within waterborne epoxy coating (WEC) and the corrosion resistance of the prepared nanocomposite coating is studied. It can be inferred from the dispersion test that g-C3N4 modified by PDA and nano-CeO2 exhibits excellent dispersion and compatibility in de-ionized water. The Electrochemical impedance spectroscope (EIS) results indicate that nanocomposite coating with PDA@g-C3N4-CeO2 exhibits the best corrosion resistance, and its low-frequency impedance (Zf=0.01Hz) is 1.78 × 109 Ω cm2, which is two orders of magnitude higher than that of pure WEC (4.27 × 107 Ω cm2). In the salt spray test, PDA@g-C3N4-CeO2/WEC also showed excellent long-term corrosion resistance with few corrosion products even after 600 h, which was consistent with the results of the EIS test. In addition, PDA@g-C3N4-CeO2/WEC also reflects the most fantastic adhesion strength (14.22 MPa), which is improved by 45.40% than that of pure WEC (9.78 MPa). Generally, the excellent protection properties of PDA@g-C3N4-CeO2/WEC are attributed to the presence of PDA and KH-550 modified nano-CeO2 on the surface of g-C3N4, which increase the compatibility and surface interactions between nanofillers and epoxy resin.

In-situ preparation of double Z-scheme Ag6Si2O7/C3N4/NH2-MIL-125(Ti) composite for visible-light photocatalytic degradation of organic pollutants in water

To develop photocatalysts with strong reactivity under visible light irradiation, economic feasibility, and superior effectiveness, based on the optimization of the binary NH2-MIL-125(Ti)/C3N4 composite proportion, Ag6Si2O7 can be deposited in situ on the surface of NH2-MIL-125(Ti)/C3N4 composite, the ternary photocatalytic composite material Ag6Si2O7/C3N4/NH2-MIL-125(Ti) has been fabricated with success. The ternary material was characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transforms infrared spectroscopy (FT-IR), ultraviolet–visible diffuse reflectance spectrum (UV-Vis DRS), photoluminescence (PL), electrochemical impedance spectroscopy (EIS) as well as X-ray photoelectron spectroscopy (XPS) analysis. The effects of the mass proportions of NH2-MIL-125(Ti) to C3N4 as well as Ag6Si2O7 to NH2-MIL-125(Ti)/C3N4 on the visible light catalytic performance were investigated. It was found that the binary composite material with a mass proportion of 1:5 of NH2-MIL-125(Ti) to C3N4 and the tertiary material with a mass proportion of 1:20 of Ag6Si2O7 to NH2-MIL-125(Ti)/C3N4 exhibited superior photocatalytic performance towards Rhodamine B (RhB) and various colorless organic contaminants, the apparent photocatalytic rate constants of the tertiary composite material for RhB, tetracycline, and ethenzamide were 15.6, 1.69 and 1.75 times that of the Ag6Si2O7 alone, and 1.30, 1.42 and 7.98 times that of the NH2-MIL-125(Ti)/C3N4 binary composite, individually. The composite maintains high efficiency after completing three cycles. The formation of active species and the effective degradation of organic contaminants during photocatalysis can be attributed to the compact double Z-scheme heterostructure among the three semiconductors in the ternary composite. The development of the double Z-scheme composite is of great significance for the economical and highly efficient elimination of organic contaminants.

Synthesis of CuO/g‐C3N4 Composite with High Anti‐Interference Ability for Enhanced Fenton‐Like Catalysis

AbstractThe combination of semiconductors and transition metal compounds for Fenton‐like application has been widely reported. However, there are still some problems that can be further studied such as the optimization of metal species and in‐depth research of mechanism. In this paper, using melamine and copper acetate as raw materials, a kind of composite of copper oxide and graphitic carbon nitride (CuO/g‐C3N4) is synthesized by a facile hydrothermal method. The synthetic conditions such as type of transition metal salt and ratio of raw material are further optimized. With the presence of H2O2, the CuO/g‐C3N4 composite shows exceptional broad‐spectrum Fenton‐like catalytic performance against the organic dyes in aqueous solution within a wide pH range, and the highest degradation rate of organic dyes can reach 99% within 10 min. After eight times of recycling, the catalytic activity of the composite can still remain more than 85%. More importantly, the CuO/g‐C3N4 composite presented excellent anti‐interference ability toward heavy metal ions and complex pollutants. Finally, the enhanced Fenton‐like catalytic mechanism is illustrated in detail.

In situ Synthesis of S‐scheme Polymer Heterojunction Poly(phenyl‐1,3,5‐yl)‐benzene)/g‐C3N4 Composites for Efficient Removal of Rhodamine B

AbstractPoly(phenyl‐1,3,5‐yl)‐benzene/g‐C3N4 (PPB/g‐C3N4) catalysts were prepared by in situ for the removal of Rhodamine B from polluted water under visible light irradiation. In addition, the catalytic behavior of PPB/g‐C3N4 composites has been studied by using XRD, TEM, UV‐vis DRS and PL. The results show that PPB has been successfully loaded on g‐C3N4, PPB/g‐C3N4‐0.4 composite have good photo‐Fenton‐like catalytic performance. In the case of PPB/g‐C3N4+H2O2 composite, the RhB photo‐ removal efficiency was ∼96 % in 50 min. The removal rate of PPB/g‐C3N4+H2O2 composite is 9.4 times higher than that of pure g‐C3N4. Owing to the higher surface area and polymer heterojunction (PHJ), PPB/g‐C3N4‐0.4 composite have the superior photo‐Fenton‐like catalytic activity. Moreover, PPB/g‐C3N4 composite rendered excellent stability. Therefore, S‐scheme polymer heterojunction PPB/g‐C3N4 composite was synthesised without metal in situ, which are potential photo‐Fenton‐like catalyst for wastewater treatment under visible‐light irradiation, in which provided a new integration strategy.

Design and Synthesis of NTU-9/C3N4 Photocatalysts: Effects of NTU-9 Content and Composite Preparation Method.

Hybrid materials based on graphitic carbon nitride (g-C3N4) and NTU-9 metal-organic frameworks (MOF) were designed and prepared via solvothermal synthesis and calcination in air. The as-prepared photocatalysts were subsequently characterized using Brunauer-Emmett-Teller (BET) analysis, UV-Vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) emission spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The obtained NTU-9/C3N4 composites showed a greatly improved photocatalytic performance for the degradation of toluene in the gas phase under LED visible-light irradiation (λmax = 415 nm). The physicochemical properties and photocatalytic activities of the obtained NTU-9/C3N4 materials were tuned by varying the NTU-9 content (5-15 wt%) and preparation method of the composite materials. For composites prepared by calcination, the photocatalytic activity increased with decreasing NTU-9 content as a result of the formation of TiO2 from the MOFs. The best photocatalytic performance (65% of toluene was photodegraded after 60 min) was achieved by the NTU-9/C3N4 sample prepared via the solvothermal method and containing 15 wt% MOF, which can be attributed to the appropriate amount and stable combination of composite components, efficient charge separation, and enhanced visible-light absorption ability. The photocatalytic mechanisms of the prepared hybrid materials depending on the preparation method are also discussed.

Preparation of 3D porous CeO2/g-C3N4 photocatalyst via facile one–step calcination for rapid removing of tetracycline

The high performance of CeO2/g–C3N4 composites were synthesized via one–step calcination process using melamine, urea and CeCl3·7H2O as starting materials and applied to the removal of tetracycline (TC) from aqueous solution under visible–light–induced photocatalytic. The as-prepared samples were characterized by XRD, FTIR, SEM, TEM, XPS, PL, BET respectively. Compared with bare g-C3N4 and bare CeO2, the as-synthesized CeO2/g–C3N4–3 composite displays a 3D porous structure constructed by nanosheets with a high surface area of 123.28 m2 g−1 and the equilibrium adsorption capacity for TC is up to 67.49 mg g−1, showing a significantly improve in structure by doping of CeO2. As a result, when 50 mg of CeO2/g–C3N4–3 photocatalyst was dispersed in 100 mL of 60 mg/L TC solution, the remove rate of TC reached 88.4% within 60 min under visible light irradiation, showing an excellent performance, which is attributed to the synergistic effect of adsorption and photocatalysis. It also shows good recyclability and stability. The radical trapping and electron spin resonance (ESR) tests manifested that the h+ radicals played the primary role in the degradation of TC, followed by ·O2− radicals.

Ag2O modified magnetic BaFe12O19/C3N4 photocatalysts with enhanced antibiotic removal: Photocatalytic mechanism and toxicity evaluation

Novel Ag2O-BaFe12O19/C3N4 composites were prepared via a grind, solvothermal and deposition–precipitation methods. The physicochemical properties of the samples were tested by FT-IR, XRD, SEM, TEM, XPS, DRS, ESR, VSM, photocurrent test, and electrochemical impedance spectra test, respectively. The characterization manifested that Ag2O was firmly anchored to the BaFe12O19/C3N4 to form heterogeneous hybrid. Most importantly, the formation of Ag2O-BaFe12O19/C3N4 effectively promoted the charge transfer, eventually enhancing the photocatalytic performance. Meanwhile, the activity of the photocatalysts were assessed by photocatalytic removal of tetracycline (TC) under visible light irradiation. The results showed that Ag2O-BaFe12O19/C3N4 photocatalyst has better photocatalytic activities than the pure component. The degradation rate reaches 80 % after 15 min, which is nearly 1.56 times higher than that of pure g-C3N4. The effects of Ag2O content, photocatalyst dosage, pH value on TC degradation performances were studied in detail, respectively. The experimental results verified that pH value exhibited significant effects on TC degradation. The TC degradation rate was highest only when the initial solution pH = 7. This indicates that the photocatalyst also has high activity in neutral environment, and no additional pH adjustment is required. The results of plant growth test (mung bean seeds) showed that the degradation intermediates showed lower toxicity. Based on experiments and characterization, the possible carrier migration and photocatalytic degradation mechanism were proposed.

Visible‐light‐driven Ni3FeN/g‐C3N4 Z‐scheme heterostructure for remarkable photocatalytic water splitting

AbstractIt is very essential to grow efficient and abundant photocatalysts for overall water cracking to produce hydrogen. Ni3FeN nanosheets were synthesized by combining simple sol–gel and calcining methods using urea as nitrogen source. A heterostructure was constructed between Ni3FeN and g‐C3N4 to enhance the absorption capacity of visible light. The reformed Z‐scheme Ni3FeN/g‐C3N4 heterojunction exhibited an excellent visible‐light photocatalytic activity. The average hydrogen evolution rate of 5 wt% Ni3FeN/g‐C3N4 composite is 528.7 μmol h−1 g−1 due to the Z‐scheme Ni3FeN/g‐C3N4 junction, which promotes the separation of photogenerated e−/h+. Interestingly, the average H2 production of Ni3FeN/g‐C3N4 is nearly 8.3 and 3.6 times higher than that of Fe4N/g‐C3N4 and Ni4N/g‐C3N4, respectively, indicating that bimetallic nitrides as cocatalysts are more conducive to enhancing the performance of photocatalysts. Importantly, the Ni3FeN/g‐C3N4 composite exhibited good cycle stability, and the hydrogen production performance hardly changed after four cycle experiments. Furthermore, photoluminescence, electrochemical impedance spectroscopy, and transient photocurrent response show that Ni3FeN/g‐C3N4 heterojunction improves the separation efficiency of photoinduced e−/h+. This work provides a feasibility of the cocatalyst Ni3FeN for use in photocatalytic hydrogen production.

Synthesis and characterization of g‐C3N4 doped with activated carbon (AC) prepared from grape leaf litters for the photocatalytic degradation of enrofloxacin in aqueous systems

AbstractThe composites of graphitic carbon nitride (g‐C3N4) doped with activated carbon (AC) were synthesized using the calcination method, and used as photocatalysts for the degradation of enrofloxacin in an aqueous system. The physical, morphology, and spectroscopic properties of the synthesized AC, bulk g‐C3N4, and AC/g‐C3N4 composites were characterized using x‐ray diffraction spectroscopy (XRD), Fourier transforms infrared spectroscopy (FTIR), Brunauer‐Emmett‐Teller method (BET), scanning electron microscopy, energy dispersive x‐ray mapping (SEM‐EDX‐mapping), transmission electron microscopy (TEM) with high resolution‐transmission electron microscopy (HR‐TEM), ultraviolet‐visible diffuse reflectance spectroscopy techniques (UV‐Vis DRS), photoluminescence spectroscopy (PL), and electron impedance spectroscopy (EIS). The AC/g‐C3N4 composites exhibited an extended visible light response and higher separation rate of photogenerated electron‐hole pairs compared to the bulk g‐C3N4. The 1 : 1AC/g‐C3N4 composite showed superior photocatalytic performance, nearly seven times higher than the bulk g‐C3N4 nanosheets, toward the degradation of enrofloxacin in aqueous solutions, under visible light irradiation. The high photocatalytic efficiency of AC/g‐C3N4 composites may be attributed to the role played by the significantly improved surface area, and the occurrence of high photoinduced charge separation, as revealed by the morphological and opto‐spectroscopic characterization of the synthesized composites, and photocatalysis experimental data. Furthermore, the AC/g‐C3N4 composites exhibited excellent recyclability and stability, making them potential candidates for use in environmental remediation.

Plasmon-induced hot carrier separation across multicomponent heterostructure in Ag@AgCl@g-C3N4 composites for recyclable detection-removal of organic pollutions via SERS sensing

The global environment is continuously being exposed to toxic organic pollutants, which also greatly threaten human health. Therefore, it is important to develop substrates for detection, identification, and removal of these organic pollutants. In this study, a multifunctional and reusable composite is prepared by anchoring Ag nanoparticles onto Cl-rich g-C3N4 nanosheets (Ag@AgCl@g-C3N4). The composites present not only excellent surface-enhanced Raman scattering (SERS) performance attributed to enhanced local electric field and SERS-active sites from the constructed structure, but also superior photocatalytic property boosted by the enhanced charge separation efficiency. These exceptional activities allow the composite to be used for detection of methylene blue with a high enhancement factor of 1.39 × 106, and a limit of detection of 1 × 10−11 M/L, as well as reusability via photocatalytic degrading the probe molecules, resulting in achieving recyclable SERS sensing applications. Furtherly, the outstanding SERS performance of the composite is demonstrated by recycling detection-degradation process for different molecules with acceptable performance decline. These results indicate that the Ag@AgCl@g-C3N4 composite provides a new path for improving traditional single-use SERS substrates and promotes practical SERS applications in sustainable detection and removal of organic pollutants.

Synthesis of SnS2/Carbon Quantum Dots/g‐C3N4 Composite and Its Photocatalytic Property

Photocatalytic degradation of organic pollutants is considered an ideal method to solve the global environmental pollution problem. In this method, photocatalytic materials are regarded as the key factor. As an n‐type photocatalytic material, graphitic carbon nitride (g‐C3N4) has attracted much attention due to its suitable bandgap, nontoxicity, and high photostability. However, g‐C3N4 still has defects such as insufficient visible light absorption, low specific surface area, and easy recombination of photogenerated electron–hole pairs, which lead to the poor photocatalytic performance of g‐C3N4. Herein, to solve the above problems, thiourea, lemon juice, and tin chloride pentahydrate are used as precursors, while carbon quantum dots (CQDs) are used as electron mediators, and the third phase SnS2 is introduced by a hydrothermal and ultrasonic composite method. SnS2/CQDs/g‐C3N4 composites with Z‐type heterojunction are successfully prepared. The results show that the SnS2/CQDs/g‐C3N4 has a 2D0D2D structure, which effectively inhibits the recombination of photogenerated electron–hole pairs, making the material have better photocatalytic degradation activity for Rhodamine B (RhB). When the mass ratio of SnS2 is 15%, the photocatalytic degradation efficiency of RhB by the composite reaches the best, which is 87.8%. After four cycles, the photocatalytic degradation efficiency of the 15% SnS2/CQDs/g‐C3N4 composite still remains at 82.9%.

ZIF-derived CoFe2O4/Fe2O3 combined with g-C3N4 as high-efficient photocatalysts for enhanced degradation of levofloxacin in the presence of peroxymonosulfate

The construction of heterostructures is an effective way of improving the photo-induced charge carrier migration rate of photocatalysts. In this study, a novel ZIF-derived CoFe2O4/Fe2O3@g-C3N4 (ZIF-CFO/[email protected]) composite was prepared using a feasible coprecipitation and high-temperature calcination approach. The separation of photo-induced charge carriers was effectively promoted due to the formation of Z-scheme heterostructure between g-C3N4 (CN) and ZIF-derived CoFe2O4/Fe2O3 (ZIF-CFO/FO). Meanwhile, combining ZIF-CFO/FO with CN could significantly boost the light response capability and reduce the bandgap of pure CN. Then, the obtained hybrid catalysts were used as an efficient mediator to activate peroxymonosulfate (PMS) for degrading levofloxacin (LVFX) under visible light illumination. The 15% ZIF-CFO/[email protected] composite exhibited the best photocatalytic performance for LVFX degradation, and LVFX of 95.1% was degraded within 40 min. Some factors influencing the degradation process in the 15% ZIF-CFO/[email protected]/Vis/PMS system are also discussed. Moreover, the mechanism of the LVFX degradation in this system was analyzed in detail based on the various characterization, LVFX degradation efficiency evaluation, radical species identification, and radical trapping results. The possible LVFX pathway was speculated based on the HPLC-MS measurement. This investigation explored the performance of photocatalysts coupled with PMS for degrading antibiotics from sewage and provided an efficient method for contaminated water treatment.

Facile one‐pot pyrolysis preparation of SnO2/g‐C3N4 composites for improved photocatalytic H2 production

AbstractBACKGROUNDGraphitic carbon nitride (g‐C3N4) has attracted extensive attention as a typical photocatalyst. However, g‐C3N4 still needs to be modified to obtain enhanced hydrogen production activity.RESULTSHere, SnO2/g‐C3N4 composites were prepared by a facile one‐pot pyrolysis method, and showed enhanced visible‐light‐driven photocatalytic H2 production activities with the highest value of 241 μmol h−1 g−1, which was about four times that of pure polymeric g‐C3N4. The facile one‐pot pyrolysis method not only promoted effective coupling between g‐C3N4 and SnO2, but also adjusted the photocatalytic performance‐related physicochemical properties of polymeric g‐C3N4. The reduction of particle sizes of g‐C3N4 promoted the migration of photogenerated carriers to the surface and the introduction of SnO2 as electron transport material promoted the transfer of photogenerated charge carriers from g‐C3N4 host photocatalyst to metallic Pt cocatalyst, synergistically restraining the recombination of photogenerated carriers. Moreover, the increased specific surface areas and pore volumes enriched the reactive sites and facilitated the mass transfer of reactants, thus accelerating the redox reactions. Furthermore, the enhanced light absorption promoted the generation of photogenerated carriers which was beneficial for photocatalytic reactions.CONCLUSIONSThis work provides an effective reference for the application of Sn species in the modification of photocatalysts, especially polymeric g‐C3N4. © 2022 Society of Chemical Industry.