Porous Graphitic Carbon Nitride Research Articles

Porous Defect-Modified Graphitic Carbon Nitride as an Effective Adsorbent for the Removal of Hg From Surface Water

Porous Defect-Modified Graphitic Carbon Nitride as an Effective Adsorbent for the Removal of Hg From Surface Water

Constructing CoP[sbnd]C/g-C3N4 nanocomposites with P[sbnd]C bond bridged interface and van der Waals heterojunctions for enhanced photocatalytic H2 evolution

Enhancing the charge transmission rate at the interface of transition metal phosphide cocatalysts is an efficient technique to reinforce the photocatalytic activity action of semiconductors, but achieving a faster interface charge transfer rate remains a challenge. This paper reported the coupling of a two-dimensional carbon layer supported CoP (CoPC) as a non-noble metal heterostructure catalyst and a two-dimensional porous graphite carbon nitride (CN) photocatalyst to enhance the transmission rate of photogenerated carriers at the interface. Detailed characterizations and mechanism research have confirmed that the PC bond and Van der Waals heterojunction at the interface function as a novel charge transmission channel, which facilitates the effective transfer of photogenerated carriers from CN to CoP. Furthermore, the large contact area exhibited by the 2D/2D Van der Waals heterojunction offers an increased number of active sites for hydrogen evolution reactions. Consequently, the composite material (CoPC/CN) formed by the coupling of CoPC and CN has an enhanced H2 production rate of 1503 μmol∙g−1∙h−1 (AQY: 3.03 % at 400 nm) and favorable H2 production stability under visible light irradiation. This investigation not only provides a new idea for the regulation of interface charge transfer pathway but also offers new inspiration for the photocatalytic system's design with the synergistic impacts of 2D/2D VDW heterojunction and chemical bonds.

Synergistic sulfur doping and nitrogen vacancies in porous graphite carbon nitride for enhanced photocatalytic H2O2 production

The oxygen adsorption ability of the photocatalyst is essential for photocatalytic production of H2O2, whereas the investigation of influence of oxygen adsorption ability on the photocatalytic H2O2 production seems to be overlooked in most studies. Herein a facile ammonium persulfate assisted hydrothermal method is developed to synthesize porous and fluffy graphite carbon nitride (CN) with sulfur doping and nitrogen vacancies. The introduction of sulfur doping and nitrogen vacancies in combination of high surface area is found to be beneficial to improve the oxygen adsorption ability, which results in the increased H2O2 yield of 293.2 μM within 4 h compared to the pristine CN (123.2 μM). The developed strategy provides new insight for the design of highly efficient photocatalysts in a facile way.

A novel method to synthesis of oxygen doped graphitic carbon nitride with outstanding photocatalytic efficiency for the degradation organic pollutants

Contamination of water sources with organic pollutants seriously threatens the environment and living organisms, so it is necessary to remove them from these sources with a proper method. Photocatalytic degradation of such pollutants can be an effective, low-cost and eco-friendly method. In this study, a new method, porous oxygen-doped Graphitic carbon nitride (POCN) photocatalyst was synthesized by pre-exfoliation of bulk graphitic carbon nitride in hydrogen peroxide followed by calcination of the resulting exfoliated and oxygenated sample at 550 °C. In fact, in this method, a combination of three strategies, nanostructure preparation, band gap engineering and defect introduction into the g-C3N4 were used to improve the efficiency of photocatalyst. The synthesized sample was characterized using XRD, FESEM, TEM, FTIR, DRS, PL, EDX, XPS, and BET-EJH. The efficiency of the prepared photocatalyst was evaluated with its ability to degrade Congo Red (CR) in aqueous solution under visible light using two light sources, LED lamp and daylight. POCN removed the CR in a short time. The degradation rate was higher under sunlight. The free radical trapping tests showed that superoxide radical anions (O2−) are the active species and are mainly responsible for color degradation.

Enhanced photocatalytic performance and mechanism of N-deficiently porous g-C3N4 in organic pollutant degradation

N-deficiently porous graphitic carbon nitride (g-C3N4) was synthesized from the mixture of melamine and urea through a one-pot co-polymerization procedure. In particular, UMCN, which was prepared with a mass ratio of 1 : 5 for melamine to urea, possesses a ultrahigh specific surface area of 183.7 m2/g. The unique structure can offer more surface active sites, narrow the bandgap, as well as enhance the separation and migration of photogenerated carriers. Consequently, UMCN exhibited fascinating photocatalytic activity in the degradation of rhodamine B (RhB), and the corresponding removal rate reached 99.3% within 30 minutes irradiated by visible light. Also, the optimal material demonstrated excellent recyclability, and the degradation rate of RhB still remained as high as 95.6% even in the 7th run. Also, UMCN presented desirable universality in eliminating other organic contaminants. This work provides a facile strategy for synthesizing high-performance g-C3N4-based photocatalyst material towards the elimination of environmental pollutants.

Porous cyclopentadiene unit-incorporated graphitic carbon nitride nanosheets for efficient photocatalytic oxidation of recalcitrant organic micropollutants in wastewater

For the purpose of searching for efficient photocatalysts to deal with recalcitrant organic micropollutants in wastewater, here an in-situ supramolecule self-assembly-thermal polymerization strategy is developed to prepare a series of porous cyclopentadiene (CPD) unit-incorporated g-C3N4 ultrathin nanosheets (CCPD-g-C3N4). The CCPD-g-C3N4 demonstrate CPD unit doping level-dependent and remarkably enhanced visible-light photocatalytic oxidation efficiency towards two organic micropollutants, acetaminophen and methylparaben, in which the optimized CCPD-g-C3N4-2 shows 6.1 and 3.5 times higher acetaminophen and methylparaben degradation rate than bulk g-C3N4; moreover, CCPD-g-C3N4-2 is still robust and efficient in the treatment of five mixed organic micropollutants in pharmaceutical wastewater, and the satisfactory micropollutant removal efficiency is obtained in a wide pH window and the presence of high concentrations of inorganic anions and cations as well as dissolved organic matters. Theoretical calculation combined with experimental test reveal that CCPD-g-C3N4 can significantly reduce ecological risk of the target pollutant after the photocatalytic degradation reaction. Such enhanced photocatalytic oxidation efficiency is dominated by the accelerated charge carrier separation dynamics and extended visible-light response region due to the incorporation of CPD units, which finally lead to the generation of abundant reactive oxygen species to degrade and mineralize target micropollutants efficiently.

Plasmonic coupling-boosted photothermal nanoreactor for efficient solar light-driven photocatalytic water splitting

Photothermal nanoreactor with rapid charge transfer and improved spectral utilization is a key point in photocatalysis research. Herein, silver sulfide quantum dots (Ag2S QDs) were coating on the surface of porous graphitic carbon nitride nano vesicles (PCNNVs) to form Ag2S/PCNNVs nanoreactors by a simple calcination method for obtaining efficient photothermal-assisted photocatalytic hydrogen (H2) evolution under simulated/real sunlight irradiation. In particularly, the as-prepared optimal 3% Ag2S/PCNNVs sample exhibited the H2 production rate of 34.8 mmol h−1 g−1, which was 3.5 times higher than that of bare PCNNVs. The enhancement of photothermal-assisted activity over the Ag2S/PCNNVs composite system is mainly attributed to the coupling of the photothermal conversion performance of Ag2S QDs and the thermal insulation performance of PCNNVs based on the plasmonic coupling-boosted photothermal nanoreactor. This study presents a promising strategy for the development of high-efficient photothermal-assisted photocatalysts.

One-Step Synthesis of Porous Graphitic Carbon Nitride and the Photocatalytic Performance under Visible-Light Irradiation

Porous graphitic carbon nitride (pg-C3N4) was synthesized via a facile one-step dicyandiamide (DCDA) high-temperature calcination method using heat-labile ammonium bicarbonate (NH4HCO3) as the gaseous template, and different pg-C3N4 materials were obtained by mixing various mass ratios of NH4HCO3 into DCDA. The micro-structures and -morphologies of the porous materials were characterized by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) respectively, and the photocatalytic degradation of methylene blue (MB) dye was tested under visible-light irradiation. It is found that the thermal decomposition of NH4HCO3 promoted destruction of the layer-structured g-C3N4 and increment of the specific surface area, producing more porous structures on the material surfaces, which is considered to be vital for the improvement of photocatalytic performance. Compared with the photocatalyst calcined by pure DCDA, the pg-C3N4 photocatalysts obtained by mixing the two raw materials performed better on MB dye degradation. Moreover, photocatalytic efficiency of the catalysts improved significantly with increasing NH4HCO3 contents in the raw materials. The degradation rate photocatalyzed by pg-C3N4 materials can reach more than 90% within 1.5 h, 6.5 times higher than that of the control material. It comes up to 99% at 2 h, basically achieving the complete degradation and decolorization of MB dye.

Broad-bandgap porous graphitic carbon nitride with nitrogen vacancies and oxygen doping for efficient visible-light photocatalytic degradation of antibiotics

Effective degradation methods are required to address the issue of antibiotics as organic pollutants in water resources. Herein, a two-stage thermal treatment method was used to prepare porous graphitic carbon nitride (g-C3N4) modified with nitrogen vacancies and oxygen doping at the N–(C)3 position and deep in the g-C3N4 framework. Compared with bulk g-C3N4 (BCN) (7 ± 1 m2/g), the modified sample (RCN-2h) possesses a larger specific surface area (224 ± 1 m2/g), a larger bandgap (by 0.19 eV), and a mid-gap state. In addition, RCN-2h shows 15.4, 11.2, and 9.5 times higher photodegradation rates than BCN for the degradation of 100% ofloxacin (OFX) (within 15 min), tetracycline (within 15 min), and sulfadiazine (within 35 min), respectively. The RCN-2h catalyst also exhibits superior stability and reusability. Systematic characterization and density functional theory calculations demonstrate that the synergistic effect of the porous structure, nitrogen vacancies, and oxygen doping in RCN-2h provides additional reaction sites, improved charge separation efficiency, and shorter diffusion paths for reactants and photogenerated charge carriers. Trapping experiments reveal that •O2− is the main active species in OFX photodegradation, and a possible photodegradation pathway is identified using liquid chromatography–mass spectrometry. Benefiting from the simplicity of synthesis methods and the superiority of elemental doping, carbon nitride materials with functional synergy have great potential for environmental applications.

Superior hydrophilic porous graphitic carbon nitride for enhanced photocatalytic hydrogen evolution

The efficient photocatalysts may significantly assist to alleviate the shortage of non-renewable resources. Whereas, the hydrophilicity of the photocatalyst greatly contributes towards the hydrogen production reaction activity. In this work, we showcased the synthesis of hydrophilic porous carbon nitride (HCN) by mixing melamine with cyanuric acid using the molten salt method. Several comprehensive spectral characterizations demonstrate that the resulting hydrophilic porous structure is associated with the emergence of cyano group. Moreover, the water contact angle experiments confirmed the enhanced hydrophilicity. The hydrogen production rate of the sample obtained is up to 465.2 μmol g-1 h−1, which is 9.38 times higher than that of the pristine carbon nitride (PCN).

Synthesis of porous g-C3N4 nanosheets with carbon vacancies for photodegradation of direct red 227 and direct black 166 dyes in aqueous solutions

Porous graphitic carbon nitride (g-C3N4) nanosheets with carbon vacancies were synthesized by recalcination of bulk g-C3N4 in a muffle furnace in static air for 2 h at 550 °C. The synthesized product (RCN) was characterized using XRD, FESEM, FTIR, DRS, PL, EDX, and BET-EJH. The photoactivity efficiency of RCN was evaluated by its ability to degrade two heavy anionic textile dyes, direct Red 227 and direct Black 166, under visible light. The results showed RCN in the presence of OH− anions can degrade the mentioned dyes under visible light in a relatively short time. The free radical trapping tests showed that ·O2− is the active species and mainly responsible for color degradation, while the OH− ions from KOH (as a co-catalyst) increased the degradation rate by trapping the photogenerated holes (h+). Combination of photocatalyst and OH− as co-catalyst was used for the first time to degrade anionic textile dyes, direct Red 227 and direct Black 166.

Mechanism insight into enhanced photocatalytic hydrogen production by nitrogen vacancy-induced creating built-in electric field in porous graphitic carbon nitride nanosheets

An appealing and efficient route to modify the catalytic behavior of g-C3N4 (gCN) is to control textures and defects at the molecular scale, which is beneficial to enhancing its built-in electric field (BIEF) and accelerating the photogenerated charge carrier separation. Herein, we deliberately design a precursors-reforming strategy for enhancing the BIEF of gCN porous microstructures through constructing N vacancies to accelerate charge separation. The N vacancies can not only enhance the BIEF, thus accelerating photocharge delocalization, but also promote reaction kinetics. Also, the porous structures offer a large number of active sites to expedite the reaction and shorten the migration distance of photogenerated carriers to the surface. As anticipated, the modified gCN exhibits a much higher photocatalytic performance, around 7.1 times that of the bulk gCN. This work will provide a fascinating method to combine textures and electronic structure regulation for gCN-based photocatalysts.

One-step synthesis of porous thin-layered graphitic carbon nitride for enhanced photocatalytic dye degradation

The application of graphitic carbon nitride (g-C3N4) as a non-metallic photocatalyst for removing harmful pollutants in the wastewater environment has received considerable attention in recent years. Nevertheless, its low activity is primarily restricted by a high rate of charge carrier recombination. Herein, a green and straightforward method for synthesizing small-sized porous thin g-C3N4 nanosheets directly from urea solution has been developed. This new photocatalyst can effectively remove 99.3% of rhodamine B within 15 min, exhibiting a degradation rate 16.8 times greater than that of conventionally synthesized bulk g-C3N4, under visible light irradiation. Additionally, this photocatalytic efficiency is comparable or even superior to that of previously reported literature, while requiring significantly less catalyst usage. From the experimental results, we have confirmed that the outstanding structural property as well as the stronger oxidizability of the valence-band holes (h+) are responsible for its greater photocatalytic activity. Its increased specific surface area and abundant pore structure significantly improve contaminant adsorption and charge separation and transfer. Meanwhile, the positive shift of the valence band enhances the oxidation of photogenerated h+, resulting in higher photocatalytic activity. This work can provide newly insights for designing highly efficient and easily-constructed g-C3N4 photocatalysts for practical photocatalytic water treatment applications.

Construction of an La-BiVO4/O-Doped g-C3N4 Heterojunction Photocatalyst Embedded in Electrospinning Nanofibers

BiVO4 has been widely used in the field of photocatalysis due to its nontoxic and moderate band gap. However, single BiVO4 has the disadvantages of a high recombination rate of photogenerated carriers and weak response to visible light, inhibiting its photocatalytic applications. To explore viable solutions, a hybrid material composed of lanthanum-doped bismuth vanadate (La-BiVO4) and oxygen-doped porous graphite carbon nitride (O-doped g-C3N4), i.e., La-BiVO4/O-doped g-C3N4 powder, was prepared by a facile hydrothermal reaction and low-temperature calcination. Then, the powder was loaded on polyacrylonitrile nanofibers (NFs) through the electrospinning fiber technique. Various surface science characterizations, including transmission electron microscopy and nitrogen absorption and desorption analysis, confirmed the successful synthesis of a mesoporous heterojunction material. The La3+-doping as well as the porous morphologies and larger specific surface area of the O-doped g-C3N4 ultimately improve the photocatalytic abilities via a proposed Z-scheme heterojunction mechanism. The roles of La3+-doping and morphology modification in promoting the separation of the photogenerated carriers and broadening the optical absorption range were experimentally discussed. The RhB degradation experiment indicated that the La-BiVO4/O-doped g-C3N4 powder has excellent photocatalytic activity, which is about 2.85 and 2 times higher than that of the pure BiVO4 and O-doped g-C3N4, respectively. Meanwhile, the La-BiVO4/O-doped g-C3N4 NF shows good stability and recoverability after a 10-cycle testing. Such a hybrid photocatalyst with a proposed Z-scheme heterojunction mechanism and good plasticity might pave a feasible way to fabricate a new library of photocatalysts.

Synergistic effect of n-π* electronic transitions in porous ultrathin graphitic carbon nitride nanosheets for efficient photocatalytic hydrogen production

The visible light absorption capacity and active sites of graphitic carbon nitride (GCN) are crucial roles for photocatalytic hydrogen (H2) production. However, the fabrication of ultrathin GCN nanosheets with enhanced light absorption via n-π* electronic transitions remain challenging. Here, we report on the successful preparation of porous ultrathin GCN nanosheets with activating n-π* electronic transitions simultaneously by microwave heating the mixture of urea and ammonium chloride (NH4Cl) compression strategy. Such the unique structure of GCN is composed of a curved porous thin layer and has numerous wrinkles that not only largely expand visible light absorption range to ∼ 650 nm but also significantly enhance the unmber of active sites and the mobility of photoexcited charges. The highest photocatalytic H2 production rate reached 99.1 μmol h−1 under visible light irradiation (λ > 420 nm), which is 8.8 folds higher than that of pristine GCN (11.2 μmol h−1). This work presents a promising and effective strategy for the engineering of GCN, which fully utilizes n-π* electronic transitions to largely expand the visible light absorption while enhancing the active sites.

One-pot synthesis of porous graphitic carbon nitride with rich nitrogen vacancies and oxygen heteroatoms for boosting photocatalytic performance

Graphitic carbon nitride (g-C3N4), as an attractive photocatalyst, has been applied in environmental pollution control and energy conversion. However, its photocatalytic performance was plagued owing to the insufficient light absorption and poor photocarrier separation and transportation efficiencies. Herein, a porous g-C3N4 with rich nitrogen vacancies and oxygen heteroatoms was fabricated using a one-pot thermal polymerization method. Such method involves molecular homogenization of urea and ammonium bicarbonate, recrystallization of urea, and subsequent polycondensation and thermal stripping of g-C3N4 lamellas. The resultant g-C3N4 presents enriched exposed edges and interconnected open diffusion channels, and possesses abundant nitrogen vacancies and oxygen heteroatoms. This unique structure and composition of g-C3N4 contribute to exposure of active sites, migration of substrate and products, and visible light absorption in photocatalytic reactions. As expected, the design of nitrogen vacancies and oxygen heteroatoms in g-C3N4 modulated its electronic structure, thereby accelerating the photocarrier separation and further accelerating the output of •O2− radicals under light irradiation. The optimal g-C3N4 exhibited an extraordinary photodegradation performance for high concentration (C0 = 50 mg/L) of Rhodamine B. The photodegradation efficiencies are 97.5% and 99% in 90 min under visible light and sunlight irradiation, respectively. The work provides a porous g-C3N4 photocatalyst with intensified photocatalytic performance for environmental pollution control and emerging energy conversion.

Template-free synthesis of M/g-C3N4 (M = Cu, Mn, and Fe) porous one-dimensional nanostructures for green hydrogen production

Herein, we synthesized porous one-dimensional graphitic carbon nitride (g-C3N4) doped atomically with metal atoms (M/g-C3N4) (M = Cu, Mn, and Fe) for the electrochemical and photo-electrochemical hydrogen evolution reaction (HER). This is driven by the direct acidification of an aqueous solution of metal precursors and melamine followed by pyrolysis at 550 °C under N2. The as-obtained M/g-C3N4 had well-defined pore sizes (5–10 nm), nanofibers (90 ± 5 nm in width and 5 ± 1 μm in length) morphology, high surface area, and M atomic contents (1.7 ± 0.2 wt.%). The HER performance is in the order of Cu/g-C3N4 > Fe/g-C3N4 > Mn/g-C3N4 in terms of the overpotential, onset potential, H2 production rate, and mass/specific activity. Notably, Cu/g-C3N4 achieved turnover frequency (TOF) close to that of commercial 10 wt.% Pt/C, but higher mass/specific activity and great H2 production rate of (222.15 μmol· g−1·h−1). This work open the doorway for the utilization of g-C3N4 doped metal-atoms at low content in electrocatalytic and photocatalytic HER.

In situ construction of oxygen deficient MoO3-x nanosheets/porous graphitic carbon nitride for enhanced photothermal-photocatalytic hydrogen evolution

In this work, the photocatalysts containing oxygen-deficient molybdenum oxide and macroscopic three-dimensional porous graphitic carbon nitride phase composite (MoO3-x/PCN) were prepared by in situ self-assembly method. The crystal phase and structure were characterized by XRD, XPS, FT-IR, SEM, and TEM measurements. Hydrogen production results showed that introducing of MoO3-x resulted in a higher hydrogen production rate of MoO3-x/PCN composite catalyst than that of PCN. Among them, the highest hydrogen production rate of 2336.15 μmol g−1 h−1 was achieved for MoO3-x-10/PCN, which was 2.23 times higher than PCN (1048.00 μmol g−1 h−1). When the reaction system temperature was 100 °C, the photothermal hydrogen production rate of MoO3-x-10/PCN was 8902.00 μmol g−1 h−1, which was 3.81 times higher than that at room temperature. PL spectra, UV–vis spectra and photoelectrochemical measurements showed that the localized surface plasmon resonance (LSPR) effect of MoO3-x effectively enhanced the photo response range and increased the temperature of the reaction system. ESR measurements showed that he composites should follow the Z-scheme charge transfer mechanism, the electrons in the CB of MoO3-x further migrate to the VB of PCN, which hinders the charge complexation in MoO3-x and PCN, improving the hydrogen production activity. This study provides a new idea for constructing a plasma-based photothermal synergistic catalytic hydrogen production strategy.

Porous chitosan-infused graphitic carbon nitride nanosheets for potential microbicidal and photo-catalytic efficacies

Supply of safe drinking water is a high-risk challenge faced internationally. Hybrid technologies involving nanomaterials can offer possible solutions to this research involving natural biopolymers. Porous chitosan with a high specific surface area has promising properties but its use as a membrane component in water purification is still rarely reported. Graphitic carbon nitride (g-C3N4) is a carbon nitride allotrope with a graphene-like layered structure that gifts unfamiliar physicochemical properties due to the presence of s-triazine fragments. It is a metal-free semiconductor with a band gap of ∼2.7 eV to ∼3.7 eV; which shows better visible light-activated photocatalyst properties. This work aims at synthesizing graphitic carbon nitride–biopolymer composite and exploring its properties in the field of wastewater treatment. The samples were synthesized via a soft chemical process with urea, as the source material. The flake-like morphology is displayed in the microstructural SEM image. The composition of the material was analyzed using EDS. Thermogram shows that the material is stable up to 500 °C and also confirms the formation of graphitic carbon nitride. In XRD spectra the intensity reduction shows the chitosan inclusion at the nitride site. The band gap of the prepared material was identified to be 2.3, 2.4 eV. The structural properties were analyzed using Fourier Transform Infrared Spectrometer and Raman spectroscopy. FTIR spectra and Raman spectra indicate the stretching vibration modes of CN and CN heterocycles and chitosan inclusion in the carbon nitride network. The photocatalytic activity was done in sunlight and a UV lamp with different dyes for doped and undoped g-C3N4. The doped (Porous/Non-porous chitosan) g-C3N4 showed faster dye degradation in sunlight compared to UV light. A biomolecular interaction study was done using Bovine serum albumin. It shows the material interaction with the BSA protein. The anti-microbial activity was performed on the Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli by disk diffusion method, the chitosan doped g-C3N4 showed good inhibitions against bacterial growth. The current work reveals the impact of nanoscale chitosan nanostructures doped on the optical, microstructural, catalytic, and antimicrobial properties of g-C3N4 nanosheets. This work provides new research options for nanocomposite-based photocatalytic nanomaterial g-C3N4 so that the quality of contaminated water could be improved.

Green and recyclable graphitic carbon nitride/chitosan/polyvinyl alcohol photocatalytic films with efficient antibacterial activity for fruit packaging

Chitosan (CS) is an excellent raw material for the preparation of food packaging films due to its good film-forming properties, non-toxicity, and biodegradability. However, pure chitosan films have drawbacks such as weak mechanical properties and limited antimicrobial activity. In this work, novel food packaging films containing chitosan, polyvinyl alcohol (PVA) and porous graphitic carbon nitride (g-C3N4) were successfully prepared. The PVA served to improve the mechanical properties of the chitosan-based films, whilst the porous g-C3N4 acted as a photocatalytically-active antibacterial agent. The tensile strength (TS) and elongation at break (EAB) of the g-C3N4/CS/PVA films both increased by ~4 times compared to the pristine CS/PVA films at the optimum g-C3N4 loading of ~10 wt%. The addition of g-C3N4 increase the water contact angle (WCA) of the films from 38° to 50°, whilst decreasing the water vapor permeability (WVP) from 160 × 10−12 to 135 × 10−12 g∙Pa−1 s−1 m−1. The shelf life of strawberries covered with g-C3N4/CS/PVA films at room temperature could be extended up to 96 h, compared to 48 h and 72 h for strawberries covered with polyethylene (PE) films or CS/PVA films, respectively. The g-C3N4/CS/PVA films offered good antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Further, the composite films could be easily recycled with the regenerated films offering almost identical mechanical properties and activities as the original films. The prepared g-C3N4/CS/PVA films thus offer promise for low-cost antimicrobial packaging applications.