Enhanced photocatalytic degradation of industrial dye by g-C3N4/TiO2 nanocomposite: Role of shape of TiO2

The photocatalytic degradation of toxic dyes has brought a new revolution to reduce water pollution. To degrade industrial dyes, TiO₂ is an important photocatalyst but the role of morphology is also important in degradation. We have synthesized g-C₃N₄/TiO₂ nanocomposite (1:1) having different shapes of TiO₂ (nanorods (NR), nanospheres (NS), and nanotubes (NT)), to show the effect of morphology on its photocatalytic activity. To improve the photocatalytic efficiency of TiO₂ in visible light, we have incorporated g-C₃N₄, a visible light active photocatalyst. The HRTEM, FESEM and Electron Diffraction studies with color mapping indicate successful synthesis of g-C₃N₄/TiO₂ nanocomposites. The increased photocatalytic efficiency of the nanocomposites regarding the degradation of Rhodamine B (RhB) dye under visible light irradiation is due to the incorporation of g-C₃N₄ with different shapes of TiO₂. The studies show that, the shape of TiO₂ has a remarkable effect in photodegradation. The best degradation performance (～97%) was obtained from g-C₃N₄/TiO₂ -nanotubes composite with a rate constant of 0.0403?min^?1 within 80?min, whereas degradation efficiency of other shapes of TiO₂ like NS (92%) and NR (94.5%) were also found to be greater than that of commercial TiO₂ (P25) composite (74%). Results from UV–Vis absorption study, X-ray Diffraction studies, X-ray photoelectron spectroscopy and BET analysis suggest that the improvement in photocatalytic activity of composite is due to increased light absorption in visible region and increase in surface area (137.1?m²/g). Results from different scavengers study (DMSO, ascorbic acid and methanol) indicate that electron and superoxide ions act as main reactive species in photodegradation of RhB dye. The reusability efficiency of the catalyst shows 86% degradation after 5 consecutive cycles. The effect of pH and catalyst concentration was also determined which shows that maximum degradation occurs at pH?～?7 (98%) and degradation efficiency is increased with increase of catalyst dose from 0.1?mg/ml to 0.6?mg/ml and after that saturation occur due to increase in opacity and scattering of light. A comparative study was done with literature which suggests that this nanocomposites act as one of the best photocatalysts for degradation of toxic dyes.     

N-TiO<Subscript>2</Subscript>/g-C<Subscript>3</Subscript>N<Subscript>4</Subscript>/Up-conversion phosphor composites for the full-spectrum light-responsive deNO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> photocatalysis

The ternary composites consisted of nitrogen-doped titanium dioxide, carbon nitride and up-conversion phosphors (UP) were successfully prepared by a solvothermal method. The heterojunction could be formed when N-TiO₂ and g-C₃N₄ were combined together. The composite of N-TiO₂/g-C₃N₄@UP had excellent ultraviolet, visible and infrared light absorption, indicating the possibility for the utilization of full spectrum of solar light. When N-TiO₂ was coupled with g-C₃N₄ and up-conversion phosphors to form a composite, the visible light and NIR light absorption of the samples increased. The ternary composite N-TiO₂/g-C₃N₄@G-UP presented reasonable deNO _x performance of about 8.0% under the irradiation of IR light of 980 nm. The intensification of the photocatalysis might be realized by utilizing up-conversion phosphors, which could convert low-energy NIR light into high-energy photons (visible light) and increase the efficient irradiation on the surface of photocatalyst.     

Preparation of a novel composite g-C3N4/TiO2/NiWO4 with enhanced photocatalytic activity toward the degradation of rhodamine B

A novel ternary heterojunction composite photocatalyst g-C₃N₄/TiO₂/NiWO₄ was fabricated using a simple hydrothermal method. The synthesized samples were characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy-dispersive spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) absorption spectra, photoluminescence (PL) spectra, transient photocurrent responses, and electrochemical impedance spectroscopies (EIS). The results indicated that the composite of g-C₃N₄/TiO₂/NiWO₄ had been successfully synthesized. By constructing a ternary heterojunction, the electron migration rate and light absorption of the material are further improved; the photogenerated electron–hole recombination is inhibited. The ternary composite photocatalyst shows the highest photocatalytic activity for the degradation of rhodamine B (RhB) than that of g-C₃N₄, TiO₂, NiWO₄, and g-C₃N₄/TiO₂ photocatalyst. The degradation efficiency of RhB using g-C₃N₄/TiO₂/NiWO₄ can reach 99% after visible-light irradiation for 40 min. Finally, the migration mechanism of charge carriers in the ternary system has been schematically illustrated by the active species capture experiment. Our research can pave the way for the fabrication of ternary heterojunction composite photocatalyst with high photocatalytic activity for the environmental contaminants treatment.

     

Novel Bi<Subscript>12</Subscript>TiO<Subscript>20</Subscript>/g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> composite with enhanced photocatalytic performance through Z-scheme mechanism

Novel Bi₁₂TiO₂₀/g-C₃N₄ composite was successfully prepared with Bi₁₂TiO₂₀ nanoparticles embedded within the fluffy crumpled g-C₃N₄ nanosheets. Bi₁₂TiO₂₀/g-C₃N₄ composites exhibit superior photoactivity and stability. As compared with g-C₃N₄ and Bi₁₂TiO₂₀, the photocatalytic efficiency of Bi₁₂TiO₂₀/g-C₃N₄ is effectively enhanced about 1.8- and 4.9-fold, respectively. Based on the trapping experiment, ^·OH and ^·O₂^? radicals are the dominant reactive oxygen species involved in the photocatalytic process. The proposed Z-scheme mechanism of charge transfer markedly promotes the carriers’ migration and separation, leading to the enhanced photocatalytic performance.     

In-situ synthesis of CdS/g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> hybrid nanocomposites with enhanced visible photocatalytic activity

A novel and simple in situ synthetic strategy was used to fabricate CdS/g-C₃N₄ hybrid nanocomposite catalysts with visible-light-driven photocatalytic activity from cadmium-containing carbon nitride compounds. X-ray diffraction measurements, high-resolution transmission electron microscopy images, and Fourier transform infrared spectra showed heterojunctions with a close interface between the g-C₃N₄ and the CdS nanoparticles and nanorods in the composite. Ultraviolet visible diffuse reflectance spectra exhibited a red shift that further presented the CdS in the polymer g-C₃N₄ skeleton, which allowed the efficient utilization of the solar spectrum for creating photogenerated electrons and holes. The photoluminescence spectra of the nanocomposites suggested charge transfer from g-C₃N₄ to CdS. The photocurrent intensity of hybrid nanocomposites was 2.3 times than that of pure g-C₃N₄ sample, and photocatalytic activity for the photodegradation of methyl orange was 2.5 times, and hydrogen evolution reaction was 2.8 times. Enhanced photocatalytic activity and photocurrent for the CdS/g-C₃N₄ hybrid nanocomposites were achieved.     

TiO<Subscript>2</Subscript>/g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> heterojunctions: <Emphasis Type="Italic">In situ</Emphasis> fabrication mechanism and enhanced photocatalytic activity

In situ fabrication of TiO₂/g-C₃N₄ (TCN) heterojunctions was achieved by a modified sol-gel method. TG analysis was employed to determine the content of TiO₂ in TCN composites. XRD, FTIR, TEM and HRTEM were used to analyze the phase composition, functional groups, morphology and microstructure of as-obtained products, respectively. Based on the measurement of surface Zeta potential of g-C₃N₄, a possible mechanism on in situ fabrication of TCN heterojunctions was concluded. The control experiments indicated that TCN heterojunctions exhibited better photocatalytic performance than either TiO₂ or g-C₃N₄, suggesting that the enchanced photocatalytic activity could be realized by TCN heterojunctions. Then, the evaluation of parameters affecting the photocatalytic performance of TCN heterojunctions was investigated. Even after five cycles, TCN heterojunctions still maintained high photocatalytic activity, exhibiting the good photocatalytic stability. UV-vis absorption spectra showed that almost all MB molecules were decomposed in the photocatalytic process. Finally, the possible mechanism on enhanced photocatalytic performance of TCN heterojunctions was discussed.     

ZnO复合石墨相氮化碳纳米片的制备及其光催化性能研究

为了提高石墨相氮化碳光催化性能,本文以尿素、硫脲、醋酸锌为前驱体,通过氧化热剥离与共混煅烧法分别制备g-C₃N₄纳米片和ZnO/g-C₃N₄异质结复合材料,并采用TEM、FTIR、XRD、UV-Vis DRS、BET等表征手段对制备的催化剂进行结构表征。以罗丹明、大肠杆菌为探针,考察了催化剂的光催化降解性能和抑菌活性。结果表明：以尿素和硫脲为前驱体,经过氧化热剥离处理后能得到的g-C₃N₄ 2D纳米片,其比表面积更大、光催化性能更加优异,且其对罗丹明的降解率较未剥离的g-C₃N₄提高了21.2%。在40 min氙灯照射下,纯g-C₃N₄并未表现出良好的抑菌性能,而通过ZnO复合制备的ZnO/g-C₃N₄异质结复合材料,在光催化降解率和抑菌活性方面均有很大提高,其中复合20%ZnO制得的ZnO异质结复合材料表现出最佳的光催化性能...     

Solar light-driven reduction of crystal violet by a composite of g-C3N4, β-Ag2Se, γ-Fe2O3 and graphite

Abstract

In this work, a new g-C₃N₄-based Z-scheme with γ-Fe₂O₃ and β-Ag₂Se both n-type semiconductors, and graphite to favor electron exchange is presented. The composite material was studied by XRD, FTIR, UV-Vis, TEM, XPS, TGA, DSC and TOF-SIMS, and the ability of this photocatalytic system to act as a photo-reductant was assessed using crystal violet (CV⁺) dye. Solar light driven photo-reduction of CV⁺ in the presence of tri-sodium citrate evidenced a synergistic enhancement of the activity of the composite toward reduction, with ～20 times higher conversion rates per unit of surface area than those of g-C₃N₄. Photo-oxidation experiments under Xe lamp irradiation in the presence of H₂O₂ also showed that the AgFeCN composite featured a higher activity (～8×) than g-C₃N₄. This Z-scheme may deserve further study as a photo-reductant to obtain hydrogen or hydrogenated compounds. Moreover, the use of CV⁺ may represent a facile procedure that can aid in the selection of new photocatalysts to be used in hydrogen production.     

Enhancement of photocatalysis performance of CdIn2S4/g-C3N4 heterojunction by H2O2 synergism

A highly efficient binary CdIn₂S₄/g-C₃N₄ heterojunction photocatalyst was synthesized by a simple wet impregnation method. Photocatalytic system based on the synergistic action of binary CdIn₂S₄/g-C₃N₄ heterojunction and H₂O₂ was proposed to improve the degradation effect of dyes. The photocatalytic activity was evaluated by the degradation of methyl orange(MO) under visible light irradiation. The results demonstrated that contrasted to pure g-C₃N₄, the synthesized heterojunction can significantly improve the photocatalytic activity. After 120 min of irradiation by visible light, the photocatalytic efficiency of MO degradation of 7CIS/CN was 3.13 times higher than that of g-C₃N₄. When 60 mM H₂O₂ was added on this basis, the photocatalytic efficiency increased from 93.81 to 99.40%. The improvement of photocatalytic activity is attributed to the formation of binary CdIn₂S₄/g-C₃N₄ heterojunction to promote the transfer of photogenerated electron-hole pairs, and an appropriate amount of H₂O₂ as an electron trap further reduced the recombination rate of photogenerated electron-hole pairs. Active species capture experiments showed that ·O₂^? are the main active substances. Subsequently, the mechanism of photocatalytic degradation was proposed. This work provided a new efficient strategy for the degradation of industrial dye wastewater.

     

Enhanced visible light photocatalytic activity for g-C<Subscript>3</Subscript>N<Subscript>4</Subscript>/SnO<Subscript>2</Subscript>:Sb composites induced by Sb doping

In this paper, g-C₃N₄/SnO₂:Sb composite photocatalysts were fabricated by in situ loading Sb-doped SnO₂ (SnO₂:Sb) nanoparticles on graphitic carbon nitride (g-C₃N₄) nanosheets via a facile hydrothermal method. The synthesized g-C₃N₄/SnO₂:Sb composites delivered enhanced visible light photocatalytic performance for degradation of rhodamine B in comparison with g-C₃N₄/SnO₂ composites without doping Sb. Various techniques including XRD, SEM, TEM, FTIR, XPS, PL and electrochemical method were employed to demonstrate the successful fabrication of g-C₃N₄/SnO₂:Sb composite and to investigate the enhanced mechanism of photocatalytic activity. The improvement of visible light absorption and the promotion of separation efficiency and interfacial transfer of photogenerated carriers induced by Sb doping were responsible for the enhancement of photocatalytic activity. This study provides a simple and convenient method to synthesize a visible light responsive catalyst with promising performance for the potential application in environmental protection.     

Efficient visible-light driven photocatalysts: coupling TiO<Subscript>2</Subscript>(AB) nanotubes with g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> nanoflakes

The wide application of the titanium dioxide (TiO₂) as the photocatalysts is greatly hindered by its intrinsic large band gap and usually fast electron–hole recombination. Here, we reported the exploration of coupling g-C₃N₄ nanoflakes to TiO₂ nanotubes with the anatase and TiO₂(B) mixed phases (TiO₂(AB)) toward the efficient visible-light-driven hybrid photocatalyst. It is found that coupling TiO₂(AB) nanotubes with g-C₃N₄ nanoflakes could bring a profoundly extension the visible light adsorption capacity and enhanced photogenerated carrier separation. Accordingly, they exhibit much higher efficient photocatalytic activities toward the degradation of sulforhodamine B under the visible light irradiation, which is enhanced for nearly 15 times to those of the TiO₂(AB) and g-C₃N₄, suggesting their promising practical applications as novel and efficient semiconductor photocatalysts for the water purification.     

Super-Photothermal Effect-Mediated Fast Reaction Kinetic in S-Scheme Organic/Inorganic Heterojunction Hollow Spheres Toward Optimized Photocatalytic Performance

Using full solar spectrum for energy conversion and environmental remediation is a major challenge, and solar-driven photothermal chemistry is a promising route to achieve this goal. Herein, this work reports a photothermal nano-constrained reactor based on hollow structured g-C₃N₄@ZnIn₂S₄ core–shell S-scheme heterojunction, where the synergistic effect of super-photothermal effect and S-scheme heterostructure significantly improve the photocatalytic performance of g-C₃N₄. The formation mechanism of g-C₃N₄@ZnIn₂S₄ is predicted in advance by theoretical calculations and advanced techniques, and the super-photothermal effect of g-C₃N₄@ZnIn₂S₄ and its contribution to the near-field chemical reaction is confirmed by numerical simulations and infrared thermography. Consequently, the photocatalytic degradation rate of g-C₃N₄@ZnIn₂S₄ for tetracycline hydrochloride is 99.3%, and the photocatalytic hydrogen production is up to 4075.65 µmol h⁻¹ g⁻¹, which are 6.94 and 30.87 times those of pure g-C₃N₄, respectively. The combination of S-scheme heterojunction and thermal synergism provides a promising insight for the design of an efficient photocatalytic reaction platform.     

Facile preparation and enhanced photocatalytic H2-production activity of Cu(OH)2 nanospheres modified porous g-C3N4

A facile precipitation approach for the preparation of Cu(OH)₂/g-C₃N₄ composite photocatalysts with good porous structure was developed for the first time. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible light (UV–vis) absorbance spectra, photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). A photocatalytic water splitting reaction on the as-prepared photocatalysts were carried out under visible light irradiation. The results revealed that the prepared samples showed significantly enhanced photocatalytic activity. The optimal Cu(OH)₂ loading content was found to be 0.34 mol%, giving an H₂-production rate of 48.7 μmol h⁻¹ g⁻¹, which is higher 16.5 times than that of pure g-C₃N₄. This high photocatalytic H₂-production activity is attributed to the presence of Cu(OH)₂ clusters on the surface of the porous g-C₃N₄, which efficiently promotes the visible light absorption and separation of photogenerated electron–hole pairs.     

g-C3N4/g-C3N4 isotype heterojunction as an efficient platform for direct photodegradation of antibiotic

A visible-light-driven g-C₃N₄/g-C₃N₄ isotype heterojunction photocatalyst was synthesized by one-step thermal treatment using urea and thiourea as the precursor. The photocatalytic activity of as-prepared photocatalyst was evaluated through the degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC) under the visible light irradiation. The hybrid showed enhanced photocatalytic activity in photodegradating the applied pollutants as compared with single g-C₃N₄. When the ratio of urea to thiourea was 2:1, the prepared isotype heterojunction exhibited the highest photocatalytic activity and the photodegradation rates for RhB and TC were 99.8% and 95.1% after being visible light irradiated for 1 h and 4 h respectively. The enhanced photocatalytic performance of the isotype heterojunction is ascribed to the enhanced charge separation efficiency. After being reused for 5 times, the hybrid still showed excellent recyclability and chemical stability. Furthermore, NaI, BQ and IPA were used as the sacrificial agents for studying the surface reactions in the photocatalytic process. The method used in this work provides a new pathway to achieve more efficient degradation of antibiotics and to stimulate further studies in this important field.     

Facile synthesis of strontium molybdate coupled g-C3N4 composite for effective tetracycline and dyes degradation under visible light

This work was designed to synthesize SrMoO₄/g-C₃N₄ heterojunction for efficient degradation of tetracycline (TC) hydrochloride via photocatalysis. SrMoO₄/g-C₃N₄ samples were prepared through a grinding and roasting process. The prepared nanocomposite exhibited excellent visible-light-driven photocatalytic activity. The reaction rate of TC photodegradation reaches 0.0171 min^?1, which is 5.9 times higher than that of neat g-C₃N₄. The origin of the high photoactivity of SrMoO₄/g-C₃N₄ was investigated using a variety of characterization techniques including XRD, FT-IR, TG, SEM, TEM, XPS, DRS, Mott-Schottky, PL, PC, and EIS. Result showed that the added SrMoO₄ was closely loaded on the g-C₃N₄ surface, which is conducive to the electron transfer between SrMoO₄ and g-C₃N₄. Mott-Schottky analysis indicated that SrMoO₄ has a lower conduction band (CB) position than g-C₃N₄. As a result, photogenerated electrons in g-C₃N₄ can move to the CB of SrMoO₄ to hinder the recombination of charge carriers, thereby increasing the photocatalytic activity under visible light. The cycling test further suggested that the SrMoO₄/g-C₃N₄ heterojunction has good stability in the photocatalytic degradation of TC. Super oxygen radicals and holes are the main reactive species.     

Novel g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> wrapped γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> microspheres heterojunction for efficient photocatalytic application under visible light irradiation

The novel g-C₃N₄ wrapped γ-Al₂O₃ microspheres heterojunction was successfully prepared by a simple hydrothermal process followed by calcination. The photocatalytic performances of the composite were evaluated by the degradation of methyl orange (MO) and rhodamine B (RhB) under visible light irradiation. The obtained Al₂O₃/g-C₃N₄ heterojunction exhibited much higher photocatalytic activity compared to pure g-C₃N₄. The enhanced performance may be mainly attributed to the tight contact between the components of the heterostructure as well as the efficient transfer of photoinduced electrons from the valence band (VB) of g-C₃N₄ to the defect sites of γ-Al₂O₃. The trapping experiment results indicated that the ·O₂ ^? radicals and holes (h⁺) are main active species in the decomposition of MO. This work will provide new ideas for manipulation of high-performance heterojunction for practical photocatalysis applications in water pollution controls.     

Flower-like SnO2/g-C3N4 heterojunctions: The face-to-face contact interface and improved photocatalytic properties

Series of SnO₂/g-C₃N₄ heterojunctions with face-to-face contact have been synthesized by a two-step process. The morphology and photocatalytic property can be adjusted by tailoring the content of g-C₃N₄ in the heterostructures. The heterojunctions present flower-like morphology and vary the size of flower with the increase of the g-C₃N₄ content. The 50% SnO₂/g-C₃N₄ heterojunctions exhibit the best performances for photodegradation of rhodamine B under solar light, which is attributed to the effective interfacial contact between SnO₂ and g-C₃N₄, leading to the increased charge transfer and prolonged charge-hole separation time. Moreover, SnO₂/g-C₃N₄ heterojunctions possess excellent stability after 4 recycling runs, because the face-to-face contact interface provides a large contact area, thus forming a close combination of two phases and guaranteeing effective separation of photogenerated carriers. Furthermore, a possible photocatalytic mechanism is analyzed and it is demonstrated that the hydroxyl radical species play an important role for the photocatalytic activity. This research highlights the promising applications of SnO₂/g-C₃N₄ heterojunctions photocatalysts in the field of water purification and environmental remediation.     

Carbon–Graphitic Carbon Nitride Hybrids for Heterogeneous Photocatalysis

Polymeric graphitic carbon nitride (g-C₃N₄) and various carbon materials have experienced a renaissance as viable alternates in photocatalysis due to their captivating metal-free features, favorable photoelectric properties, and economic adaptabilities. Although numerous efforts have focused on the integration of both materials with optimized photocatalytic performance in recent years, the direct parameters for this emerging enhancement are not fully summarized yet. Fully understanding the synergistic effects between g-C₃N₄ and carbon materials on photocatalytic action is vital to further development of metal-free semiconductors in future studies. Here, recent advances of carbon/g-C₃N₄ hybrids on various photocatalytic applications are reviewed. The dominant governing factors by inducing carbon into g-C₃N₄ photocatalysts with involving photocatalytic mechanism are highlighted. Five typical carbon-induced enhancement effects are mainly discussed here, i.e., local electric modification, band structure tailoring, multiple charge carrier activation, chemical group functionalization, and abundant surface-modified engineering. Photocatalytic performance of carbon-induced g-C₃N₄ photocatalysts for addressing directly both the renewable energy storage and environmental remediation is also summarized. Finally, perspectives and ongoing challenges encountered in the development of metal-free carbon-induced g-C₃N₄ photocatalysts are presented.     

SnO2/g-C3N4 photocatalyst with enhanced visible-light photocatalytic activity

Visible light-responsive SnO₂/g-C₃N₄ nanocomposite photocatalysts were prepared by ultrasonic-assisting deposition method with melamine as a g-C₃N₄ precursor. The as-prepared photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectra and photoluminescence emission spectra. The photocatalytic activities of the samples were evaluated by monitoring the degradation of methyl orange solution under visible light irradiation (wavelength ≥400 nm). The results show that the SnO₂ nanoparticles with the size of 2–3 nm are dispersed on the surface of g-C₃N₄ evenly in SnO₂/g-C₃N₄ nanocomposites. The visible-light photocatalytic activity of SnO₂/g-C₃N₄ nanocomposites is much higher than that of pure g-C₃N₄, and increases at first and then decreases with the increment of the content of g-C₃N₄ in the nanocomposites. The visible-light photocatalytic mechanism of the investigated nanocomposites has been discussed.     

In<Subscript>2</Subscript>S<Subscript>3</Subscript> nanoparticles dispersed on g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> nanosheets: role of heterojunctions in photoinduced charge transfer and photoelectrochemical and photocatalytic performance

Fast recombination of photogenerated charge carriers is a major problem in the photoelectrochemical and photocatalytic processes. In this work, we report significantly improved PEC performance of a nanocomposite consists of In₂S₃ nanoparticles dispersed on g-C₃N₄ nanosheets synthesized by a simple and facile wet chemical route. The results of high-resolution TEM study show that the obtained In₂S₃ nanoparticles of size 10–20 nm exist in cubic phase and are uniformly dispersed on the surface of g-C₃N₄ nanosheets. The In₂S₃/g-C₃N₄ nanocomposite with 25 weight percentage of In₂S₃ exhibits 8.5 times higher photocurrent density than the single-phase g-C₃N₄ under visible light illumination. The enhanced photocurrent density exhibited by the In₂S₃/g-C₃N₄ nanocomposite is attributed to the efficient separation of photogenerated charge carriers. The charge transfer mechanism in In₂S₃/g-C₃N₄ heterojunction was studied by a series of experiments, such as electrochemical impedance spectroscopy, photoelectrochemical measurement and photoluminescence emission spectroscopy. The intimate interface promotes the charge transfer and inhibits the recombination rate of photogenerated electron–hole pairs, which significantly improves the photoelectrochemical performance. A detailed charge transfer mechanism is discussed based on the Mott–Schottky plot study. This heterojunction material is found to be an efficient photocatalyst for the degradation of both cationic rhodamine B dye and anionic methyl orange dye as the lifetime of photogenerated charge carriers is higher in the composite than in single-phase In₂S₃ and g-C₃N₄. A strong correlation between the photoelectrochemical and the photocatalytic performances is observed in this composite.