g-C3N4 Sheets Research Articles

Concerted catalytic and photocatalytic degradation of organic pollutants over CuS/g-C3N4 catalysts under light and dark conditions

Organic pollutants in industrial and agricultural sewage are a serious threat to the environment and human health. Achieving continuous photocatalytic degradation of organic pollutants under light and dark conditions would have exciting implications for practical sewage treatment. In this paper, CuS/g-C3N4 composite catalysts with CuS nanoparticles anchored on g-C3N4 sheets were successfully fabricated via a simple solvothermal reaction. The morphology, structure, optical absorption characteristics, electron–hole recombination rate, and degradation performance of the as-prepared CuS/g-C3N4 catalysts were investigated in detail. The results confirmed that the as-fabricated CuS/g-C3N4 catalysts exhibited high Fenton-like catalytic degradation efficiencies in the dark, and rapid concerted Fenton-like catalytic, direct H2O2 photocatalytic and CuS/g-C3N4 photocatalytic degradation activities under visible light. Thus, the as-fabricated CuS/g-C3N4 catalysts can degrade organic pollutants continuously during both day and night. These degradation properties, along with the simple catalyst fabrication process, will facilitate the practical application of this system in the continuous removal of organic pollutants.

Photocatalytic Inactivation of Bacteriophage f2 with Ag3PO4/g-C3N4 Composite under Visible Light Irradiation: Performance and Mechanism

Water-borne virus pollution has caused great harm and attracted widespread attention in many countries. Visible-light-driven photocatalysis is considered as a promising process for disinfection. In this study, Ag3PO4/g-C3N4 (AgCN) composites were synthesized by hydrothermal method. The photocatalytic disinfection was investigated using bacteriophage f2 as the model virus. Moreover, the effects of pH and humic acid on photocatalytic disinfection were studied. Meanwhile, the mechanism of enhanced disinfection by Ag3PO4/g-C3N4 was systematically investigated by radical scavenger experiments. The results show that Ag3PO4 particles were uniformly distributed on g-C3N4 sheets. By means of photoluminescence spectrometer analysis, it is confirmed that a lower carrier recombination rate for Ag3PO4/g-C3N4 was achieved compared with Ag3PO3 and g-C3N4. Meanwhile, complete inactivation of f2 with concentration of 3 × 106 PFU/mL was reached within 80 min in the presence of Ag3PO4/g-C3N4 composite. The pH had little effect on removal efficiency overall, while the existence of humic acid resulted in a significant negative effect on the inactivation of f2 due to the optical shielding and absorption of humic acid. Recycling tests of Ag3PO4/g-C3N4 confirmed that Ag3PO4/g-C3N4 presented superior stability. The results from radical scavenger experiments indicated that holes (h+) and hydroxyl radicals (·OH) played important roles in photocatalytic disinfection process.

Highly Active, Superstable, and Biocompatible Ag/Polydopamine/g-C3N4 Bactericidal Photocatalyst: Synthesis, Characterization, and Mechanism

The goal of this paper is to develop a bactericidal photocatalyst silver/polydopamine/graphitic carbon nitride (Ag/PDA/g-C3N4) as a new type of antibacterial material with high activity, superstability, and excellent biocompatibility. Small Ag NPs (3.6–10.5 nm) disperse uniformly on the PDA-modified g-C3N4 sheets. This biophotocatalyst has excellent antibacterial activity against Escherichia coli, including low MIC100%Ag of 9.5 ppm and MBC100%Ag of 6.3 ppm but also a low cytotoxicity for human umbilical vein endothelial cells (HUVECs) because of biocompatible PDA. After 30 days in an air environment, only 0.18% of Ag+ was detected, which indicated the superstability of this biophotocatalyst compared with the state-of the-art antibacterial materials. The possible bactericidal mechanism is the synergistic effect between photocatalytic PDA-modified g-C3N4 and active Ag NPs. The Ag NPs themselves have strong antibacterial activity due to their small sizes. Importantly, under light irradiation, the surface plasmonic effect of Ag NPs and the incorporation of PDA enhance the photocatalytic activity of g-C3N4 significantly by increasing its light absorption, improving photoconductivity for photogenerated electrons and holes, and inhibiting their recombination. As a result, the sufficient radicals such as •OH and O2•– radicals can be formed. The radicals, particularly •OH, together with holes, can accelerate the death of bacteria through the destruction of biomolecules.

Facile fabrication of BiOCl/RGO/protonated g-C3N4 ternary nanocomposite as Z-scheme photocatalyst for tetracycline degradation and benzyl alcohol oxidation

A novel ternary BiOCl/RGO/PCN nanocomposite was successfully fabricated through coupling-protonated g-C3N4 (PCN) sheets with GO by electrostatic attraction, followed by in situ synthesis of BiOCl layers on the surface on PCN/GO via hydrothermal reaction and simultaneously achieving the reduction in GO. The as-prepared BiOCl/RGO/PCN composite exhibited significantly enhanced photoactivities toward the degradation of representative antibiotic tetracycline and selective aerobic oxidation of benzyl alcohol compared to pristine g-C3N4, protonated g-C3N4, pure BiOCl and binary BiOCl/PCN composite under simulated solar light irradiation. The structure–property relationship was explored by several effective characterization techniques. The results show that RGO coordinated well with two semiconductors of BiOCl and PCN, and BiOCl/RGO/PCN composite with closely contacted interface exhibited broad optical adsorption range and effective photogenerated charge carrier separation efficiency, which are attributed to the improved photocatalytic performance. The results also demonstrate that a Z-scheme charge process was formed between BiOCl and PCN with RGO serving as electron transfer medium to promote the fast transporting of photoinduced electrons. Therefore, more photoinduced electrons and holes could retain in the CB of PCN and in the VB of BiOCl with strong redox ability, respectively, which is beneficial to the further effective generation of active radicals participating in photocatalytic reaction. This work provides a promising Z-scheme ternary photocatalyst with facile synthetic method and potential application in environmental pollution elimination and green oxidative organic transformation.

Synthesis of Z-scheme g-C3N4/Ag/Ag3PO4 composite for enhanced photocatalytic degradation of phenol and selective oxidation of gaseous isopropanol

In this study, g-C3N4/Ag/Ag3PO4 composites were constructed by a simple in situ deposition method at room temperature, in which Ag3PO4 particles with regular rhombic dodecahedrons morphology were finely coated on the surface of the g-C3N4 sheet. The g-C3N4/Ag/Ag3PO4 exhibited much improved activity comparing with other classic catalysts such as g-C3N4 and Ag3PO4. The optimal photocatalyst (AC1.0) with Ag3PO4/g-C3N4 ratio of 1 could dramatically decompose phenol under visible-light irradiation, which showed a degradation rate of 1.13 min−1 and almost 60 and 2.5 times higher than that of pure g-C3N4 and Ag/Ag3PO4, respectively. After 3 cycling run tests, the AC1.0 photocatalyst still maintained high photocatalytic activity. Electron paramagnetic resonance spectroscopy and radical quenching tests were employed to investigate hydroxyl and superoxide radicals for organic degradation processes. Furthermore, the photocatalytic activity of AC1.0 was also tested for gaseous isopropanol (IPA). After 4 h irradiation, 63% of IPA was oxidized with acetone as main outcome product. The highly efficient separation of photogenerated electron-hole pairs was attributed to the construction of Z-scheme mechanism.

Narrowing the band gap of graphitic carbon nitride sheet by coupling organic moieties: A DFT approach

A series of composite materials based on graphitic carbon nitride (g-C3N4) sheet were designed and investigated. The g-C3N4 sheet has been coupled with wide gaped organic molecules to reduce the band gap of the composite materials. Out of the five composites, g-C3N4-A shows excellent optical and electronic properties. In this case, the band gap of g-C3N4 sheet has been reduced from 3.65 to 2.65 eV. Besides, the angle between the g-C3N4 sheet and the organic molecular plane becomes approximately 90°, which minimizes the rate of recombination of the electron-hole pair.

Noble metal-free modified ultrathin carbon nitride with promoted molecular oxygen activation for photocatalytic formaldehyde oxidization and DFT study

Modifying the electronic structure of photocatalysts is an important approach for increasing the separation efficiency of photogenerated carriers and activating molecular oxygen into superoxide radical (O2−) for contaminants removal. Herein, based on the density functional theory (DFT) calculations, we found that doping F− can not only narrow the bandgap of graphitic-phase carbon nitride (g-C3N4), but also decrease the electronic localization, extend the π conjugated system and increase the in-planar electron density, resulting in promoting the molecular oxygen activation of g-C3N4. The experiments indicated that the fluorinated ultrathin g-C3N4 was favorable for activating molecular oxygen into O2− under visible light irradiation, which could be ascribed to the relatively higher conduction band position and more negative surface adsorption energy for O2 as well as advantageous charge accumulation on adsorbed O2 as compared to ultrathin g-C3N4. By virtue of the synergic effect of enhanced adsorption ability to O2, effective separation of photogenerated carriers and more reductive photoexcited electrons derived from the ultrathin structure and F− associates, the fluorinated ultrathin g-C3N4 sheets revealed promoted solar driven photocatalytic activity for formaldehyde (HCHO) oxidation. This study could provide new insights into the mechanistic comprehension of molecular oxygen activation reaction and design of low cost noble metal-free modified ultrathin layered photocatalysts with for environmental remediation.

Fabrication of highly efficient TiO2/C3N4 visible light driven photocatalysts with enhanced photocatalytic activity

Mesoporous TiO2/g-C3N4 nanocomposites with different TiO2 weight percentages have been synthesized using template as structure directing agent under mild hydrothermal conditions. XRD diffraction patterns exhibited the crystalline anatase phase of TiO2 along with distinguished peak for g-C3N4. Raman spectroscopy and FT-IR indicated the presence of TiO2 and g-C3N4 in designed heterojunctions. TEM images showed high crystallinity of TiO2 nanoparticles (size ∼15–20 nm) with porous network dispersed on 2D layered g-C3N4 sheets. N2 sorption analysis revealed large pore volume and high surface area of TiO2/g-C3N4 nanocomposites along with the mesoporous nature of TiO2. The photocatalytic efficiency of designed photocatalysts was assessed by photodegradation of methylene blue through visible light illumination. All TiO2/g-C3N4 nanocomposites revealed superior photocatalytic performance than both pure g-C3N4 and mesoporous TiO2. 10%TiO2/g-C3N4 nanocomposites revealed the highest photocatalytic performance among all prepared samples owing to its large surface area, extended visible light utilization, perfectly formed heterojunction and excellent mobility of charge carriers within the mesoporous framework. A mechanism for the destruction of MB has also been proposed. Continuous efforts for designing “smart” photocatalytic material showing wide spectral response in visible region is the present desire for the destruction of harmful pollutants.

Interfacial coupling induced direct Z-scheme water splitting in metal-free photocatalyst: C3N/g-C3N4 heterojunctions

Mimicking the natural photosynthesis in green plants, artificial Z-scheme photocatalysis enables more efficient utilization of solar energy for photocatalytic water splitting. Most currently designed g-C3N4-based Z-scheme heterojunctions are usually based on metal-containing semiconductor photocatalysts, thus exploiting metal-free photocatalysts for Z-scheme water splitting is of huge interest. Herein, we propose two metal-free C3N/g-C3N4 heterojunctions with the C3N monolayer covering g-C3N4 sheet (monolayer or bilayer) and systematically explore their electronic structures, charge distributions and photocatalytic properties by performing extensive hybrid density functional calculations. We clearly reveal that the relative strong built-in electric fields around their respective interface regions, caused by the charge transfer from C3N monolayer to g-C3N4 monolayer or bilayer, result in the bands bending, renders the transfer of photogenerated carriers in these two heterojunctions following the Z-scheme instead of the type-II pathway. Moreover, the photogenerated electrons and holes in these two C3N/g-C3N4 heterojunctions can not only be efficiently separated, but also have strong redox abilities for water oxidation and reduction. Compared with the isolated g-C3N4 sheets, the light absorption in visible to near-infrared region are significantly enhanced in these proposed heterojunctions. These theoretical findings suggest that these proposed metal-free C3N/g-C3N4 heterojunctions are promising direct Z-scheme photocatalysts for solar water splitting.

Metal-doped graphitic carbon nitride (g-C3N4) as selective NO2 sensors: A first-principles study

In this research, the potential application of metal-doped g-C3N4 as highly sensitive molecule sensors for NO2 detection was studied using density function theory (DFT) calculations. Various metal-doped (Ag-, Au-, Co-, Cr-, Cu-, Fe-, K-, Li-, Na-, Mn-, Pt-, Pd-, Ti-, V-) g-C3N4 sheets were considered. CO, CO2, NH3, N2 and NO2 molecules were found to adsorb on metal-doped g-C3N4via strong chemical bonds. Chemisorbed gas molecules and metal-doped g-C3N4 formed charge transfer complexes with different charges transferring from metal-doped g-C3N4 to gas molecules. Pristine and metal-doped g-C3N4 sheets were demonstrated as potential capturers for certain gas molecules according to the adsorption energy, isosurface of electron density difference, and density of states analysis. Among the diverse metal-doped g-C3N4 sheets, Ag-, K-, Na-, and Li-doped g-C3N4 were found to be clearly sensitive to the NO2 molecule. The adsorption energies between NO2 and Ag-, K-, Na-, and Li-doped g-C3N4 were significantly greater than those of the other gas molecules (CO, CO2, N2, and NH3). The density of states indicates that the NO2 adsorption on Ag-, K-, Na-, and Li-doped g-C3N4 induced the shift of the total density of state in the positive energy direction. Charge transfer results also demonstrate that chemical interactions existed between NO2 and Ag-, K-, Na-, and Li-doped g-C3N4. All these results suggest the strong potential of Ag-, K-, Na-, and Li-doped g-C3N4 for application as highly sensitive molecule sensors.

Construction of g-C₃N₄-mNb₂O₅ Composites with Enhanced Visible Light Photocatalytic Activity.

A series of composites consisting of g-C3N4 sheet and mesoporous Nb2O5 (mNb2O5) microsphere were fabricated by in situ hydrolysis deposition of NbCl5 onto g-C3N4 sheet followed by solvothermal treatment. The samples were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), N2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of the composites was studied by degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) in aqueous solution under visible light irradiation (λ > 420 nm). Compared with g-C3N4 and mNb2O5, g-C3N4-mNb2O5 composites have higher photocatalytic activity due to synergistic effect between g-C3N4 and mNb2O5. Among these composites, 4% g-C3N4-mNb2O5 has the highest efficiency and good recyclability for degradation of both RhB and TC-HCl.

CeO2/g-C3N4 nanocomposite: A perspective for electrochemical sensing of anti-depressant drug

Herein, a binary composite electrode comprising CeO2 nanoparticles and g-C3N4 sheets were investigated for electrochemical determination of an anti-depressant drug Agomelatine (AG). The nanocomposite was utilized for fabrication of glassy carbon electrode (GCE) via simple casting method and characterized for morphology and composition using various advanced characterization tools which indicated successful loading of CeO2 nanoparticles on g-C3N4 sheets. The modified sensor was employed for electrochemical study of AG using cyclic voltammetry (CV) and square wave voltammetry (SWV). A significant enhancement was observed in anodic peak current at CeO2/g-C3N4/GCE, as compared to bare electrode, due to reduction in charge transfer resistance and augmentation in electron transfer process. Electroactive surface area of modified sensor was found to be 0.204 cm2 which was almost 8 times higher than bare electrode. A diffusion-limited process involving equal number of protons and electrons controlled the electrochemical oxidation of AG with the sensor. Under optimized conditions, the modified sensor displayed linear response over a concentration range of 1-20 ng/ml, limit of detection (LOD) 0.96 ng/ml and limit of quantification (LOQ) 2.92 ng/ml. The developed method was successfully applied to determine AG in commercial tablets with satisfactory recovery results along with good reproducibility, selectivity and stability.

α-MnO2 nanorods supported on porous graphitic carbon nitride as efficient electrocatalysts for lithium-air batteries

Synthesis of α-MnO2 nanorods grown on porous graphitic carbon nitride (g-C3N4) sheets via a facile hydrothermal treatment gives a porous composite exhibiting higher activity for an air cathode than the individual component of α-MnO2 or porous g-C3N4 for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The porous g-C3N4/α-MnO2 composite also exhibits better performance in a Li-air battery than pure α-MnO2 or XC-72 carbon catalysts, which includes superior discharge capacity, low voltage gap and high cycle stability. The α-MnO2 nanorods catalyze the OER and the porous g-C3N4 sheets catalyze the ORR.

Construction of hybrid Z-scheme graphitic C3N4/reduced TiO2 microsphere with visible-light-driven photocatalytic activity

A novel Z-scheme graphitic C3N4/reduced TiO2 microsphere (g-C3N4/r-TiO2) has been successfully synthesized by a solvothermal method. The as-prepared samples with different contents of g-C3N4 were characterized by X-ray diffraction, electron paramagnetic resonance, scanning electron microscope, UV–vis. diffuse reflectance and photoluminescence spectra. The r-TiO2 microspheres are aggregated on the surface of g-C3N4 sheets in the as-prepared g-C3N4/r-TiO2 composites. All g-C3N4/r-TiO2 catalysts show enhanced photocatalytic activity for the degradation of rhodamine B under visible light irradiation. It could be attributed to these influences of oxygen vacancy (changing the band gap of TiO2), the large specific surface area (providing much more active sites for photocatalytic reaction), and the synergetic effect between g-C3N4 and r-TiO2 (promoting the separation for photoinduced electron-hole pairs). Moreover, the Z-scheme carriers transfer mechanism in the photocatalytic process has been discussed through trapping experiments of active species. The work demonstrates the strategies of the construction of Z-scheme carriers transfer system, the introduction of oxygen vacancy and structure designing are beneficial to design materials toward solar energy conversion like contaminant degradation.

Enhanced photocatalytic property of hybrid graphitic C3N4 and graphitic ZnO nanocomposite: the effects of interface and doping

Using first-principles calculations, we present a potential new way to improve the photocatalytic efficiency of the g-C3N4 sheet by coupling with the g-ZnO sheet to form heterojunction nanostructure followed by the addition of N atom at an atomic level. The result indicates the g-C3N4/g-ZnO heterojunction is a staggered band alignment (type II) structure and a polarized field is generated by the electrons transfer across the interface simultaneously, which facilitate the separation of e−–h+ pairs and promote the photocatalytic activity. Furthermore, a great difference in energy levels between redox potentials and band edges of the C3N4/g-ZnO nanocomposite ensures that the water splitting/CO2 reduction reaction is energetically favored. In addition, through the incorporation of nitrogen dopant, the g-C3N4/N-g-ZnO nanocomposite displays desirable properties. The N-derived doping peak causes a decrease of the band gap width of the g-C3N4/g-ZnO nanocomposite, resulting in the enhanced optical absorption from UV into visible light. This theoretical predictions provide insightful outlooks in understanding the effects of interface and doping on the enhanced photocatalytic property of the g-C3N4/g-ZnO nanocomposites, which will assist in engineering highly efficient g-C3N4-based photocatalysts.

Adsorption and photocatalytic study of dye degradation over the g‐C 3 N 4 /W 18 O 49 nanocomposite

A heterogeneous nanocomposite (NC) of g-C 3 N 4 /W 18 O 49 based on the coupling of W 18 O 49 nanorods (NRs) with the graphitic carbon nitride (g-C 3 N 4 ) sheets has been synthesised via a solvothermal method. The as-synthesised products were characterised by X-ray diffraction, X-ray photoelectron spectrometry, and transmission electron microscopy. The g-C 3 N 4 /W 18 O 49 NC exhibited very strong adsorption ability towards the methylene blue (MB) dye and demonstrated a high removal efficiency of 99.14% after 0.5 h equilibration in dark. Compared to the g-C 3 N 4 sheets and W 18 O 49 NRs, the g-C 3 N 4 /W 18 O 49 NC exhibited higher removal efficiencies towards both the MB and methyl orange (MO) dyes via a combination of adsorption and degradation. The photocatalytic process of the g-C 3 N 4 /W 18 O 49 NC followed the Z-scheme photocatalytic mechanism. This work provides an efficient strategy for the synthesis of g-C 3 N 4 -based heterogeneous photocatalysts.

Hydrothermal Synthesis of a New Kind of N-Doped Graphene Gel-like Hybrid As an Enhanced ORR Electrocatalyst.

In this work, g-C3N4@GO gel-like hybrid is obtained by assembling intentionally exfoliated g-C3N4 sheets on graphene oxide (GO) sheets under a hydrothermal condition. A specific N-doping process is first designed by heating the g-C3N4@GO interlaced hybrid in vacuum to form nitrogen-doped graphene nanosheets (NGS) with high level of pyridinic-N (56.0%) and edge-rich defect structure. The prepared NGS exhibited a great electrocatalysis for oxygen reduction reaction (ORR) in terms of the activity, durability, methanol tolerance, and the reaction kinetics. And the excellent electrocatalytic performance stems from the effective N-doped sites that the nitrogen atom is successfully doped at the defective edges of graphene, and the annealing temperature can play significant role of the doping pattern and location of N. The research provides a new insight into the enhancement of electrocatalysis for ORR based on nonmetal carbons by using the novel N-doping method.

Facile fabrication of nanosized graphitic carbon nitride sheets with efficient charge separation for mitigation of toxic pollutant

Delamination of layer semiconductor materials into two-dimensional sheets can bring superior properties such as surface area, intrinsic carrier mobility and band structure. In this study, inerratic nanosized graphitic carbon nitride (g-C3N4) sheets with the lateral size of approximately 100 ± 50 nm are conveniently fabricated by ultrasonic exfoliation of bulk g-C3N4 that derived from thermolysis of dicyandiamide after recrystallization. The nanosized g-C3N4 sheets exhibit excellently higher photocatalytic performance toward aflatoxin B1 (AFB1) degradation under visible light than that of bulk g-C3N4. And the enhanced photocatalytic mechanisms are mainly due to the better photogenerated charges separation and larger surface area of nanosized g-C3N4 sheets, which are systematically confirmed by physicochemical and photoelectric characterization. Through identification of products structure, it is found that the initial photodegradation intermediate (C17H14O7) or main products (C14H16O4 and C12H10O4) of AFB1 after 2 h irradiation over bulk g-C3N4 and nanosized g-C3N4 sheets are different, which may be attributed to the photoactivities and number of active groups from both catalysts during photoreaction. Therefore, this work may provide referential information for preparation of inerratic nanosized sheets and understand the related photodegradation mechanism of aflatoxin B1.

Construction of Ag/g-C3N4 photocatalysts with visible-light photocatalytic activity for sulfamethoxazole degradation

Ag/g-C3N4 was successfully synthesized by a photo-reduction method. By using PVP as a protecting agent, Ag nanoparticles were uniformly dispersed on g-C3N4 sheets and the average diameter (ca. 20 nm) of Ag nanoparticles were well controlled when increasing Ag content from 1 wt% to 10 wt%. The visible-light-induced photocatalytic activity of Ag/g-C3N4 was investigated by the degradation of sulfamethoxazole (SMX). The results exhibited that Ag/g-C3N4 displayed excellent visible-light photocatalytic performance. Compared with g-C3N4, the removal efficiency of SMX by 5 wt% Ag/g-C3N4 was increased by 32.1% and the TOC removal was increased by 11.5% due to the SPR effect of Ag nanoparticles. Compared with Ag/g-C3N4 synthesized without PVP, the removal efficiency of SMX by the 5 wt% Ag/g-C3N4 was increased by 10.2%. Photogenerated holes and O2− radicals were identified as the main active species and three intermediates were identified in SMX degradation by 5 wt% Ag/g-C3N4, which were the same as that by g-C3N4, but the changing trend of produced intermediates was different. The produced intermediates of m/z 99 and m/z 270 can be further degraded by 5 wt% Ag/g-C3N4, but not by g-C3N4. The 5 wt% Ag/g-C3N4 also exhibited superior photocatalytic performance on the photodegradation of SMX in real waters, such as surface water and WWTP secondary effluent. This work may provide an appealing strategy on green remediation of contaminated water environment.

Combination of Ag2CrO4 and AgI semiconductors with g-C3N4: Novel nanocomposites with substantially improved photocatalytic performance under visible light

Novel g-C3N4/Ag2CrO4/AgI nanocomposites with improved photocatalytic performance under visible light were synthesized by consecutive deposition of Ag2CrO4 and AgI semiconductors over g-C3N4 sheets by refluxing method. The synthesized g-C3N4/Ag2CrO4/AgI photocatalysts were fully characterized by XRD, EDX, SEM, TEM, UV–vis DRS, TGA, FT-IR, and PL instruments. Photocatalytic performance of g-C3N4/Ag2CrO4/AgI (30%) nanocomposite for degradation of RhB was 27.9, 4.0, and 3.1 folds greater than those of the g-C3N4, g-C3N4/Ag2CrO4 (20%), and g-C3N4/AgI (30%) photocatalysts, respectively. The substantially increased photocatalytic performance was related to efficient retardation of the charge carriers from recombination and more absorbing of visible light, due to the synergistic effects of Ag2CrO4 and AgI on g-C3N4. The photocatalytic performance of the ternary nanocomposite did not considerably change after several cycles, indicating that the ternary nanocomposite is stable and it could be reused in successive runs.