3N4 Heterojunction Research Articles

Enhanced Degradation of Norfloxacin Under Visible Light by S-Scheme Fe2O3/g-C3N4 Heterojunctions.

S-scheme Fe2O3/g-C3N4 heterojunctions were successfully fabricated by the ultrasonic assistance method to remove norfloxacin (NOR) under visible light irradiation. The synthesized catalysts were well studied through various techniques. The obtained Fe2O3/g-C3N4 heterojunctions exhibited an optimal photocatalytic degradation of 94.7% for NOR, which was 1.67 and 1.28 times higher than using Fe2O3 and g-C3N4 alone, respectively. In addition, the kinetic constant of NOR removal with Fe2O3/g-C3N4 composites was about 0.6631 h-1, and NOR photo-deegradation was still 86.7% after four cycles. The enhanced photocatalytic activity may be mainly attributed to the formation of S-scheme Fe2O3/g-C3N4 heterojunctions with built-in electric fields, which were beneficial to the separation and transfer of photostimulated charge carriers. Furthermore, a possible photo-degradation mechanism of NOR for S-scheme Fe2O3/g-C3N4 heterojunctions is described.

High-efficiency PMS activation by difunctional Co-Fe PBA/g-C3N4 S-scheme heterojunction for oxytetracycline degradation: Performance evaluation and mechanism insight

The utilization of sulfate radical-based advanced oxidation processes (SR-AOPs) has captivated the academic community due to their minimal energy requirements and superior efficacy in peroxomonosulfate (PMS) activation for pollutant decomposition. Notwithstanding these advantages, engineering an effective and economical catalyst for PMS activation presents a considerable hurdle. In the present study, a metal-organic framework of CoFe PBA is ingeniously anchored onto g-C3N4 nanosheets, resulting in the formation of an innovative CoFe PBA/g-C3N4 S-scheme heterojunction that demonstrates remarkable efficiency in PMS activation. Intriguingly, the catalytic efficiency of CoFe PBA/g-C3N4 surpasses that of g-C3N4 and CoFe PBA by 7-fold and 2.33-fold, respectively. The heightened activity of CoFe PBA/g-C3N4 heterojunction is attributed to the enhanced charge transfer efficiency, a consequence of the successful heterojunction formation. Concurrently, the ability of photoexcited electrons to reduce Co3+/Fe3+ to Co2+/Fe2+ bolsters PMS activation. Significantly, this heterojunction retains unparalleled stability in degrading oxytetracycline without discernible performance attenuation, heralding its commendable prospects in real-world applications. Besides, mechanism exploration indicates that SO4−, h+, and electron transfer contribute to oxytetracycline degradation in the CoFe PBA/g-C3N4 system. This investigation serves as a beacon for the strategic development of highly active and stable catalysts for PMS activation, aiming at environmental decontamination.

Design of MnO2/g-C3N4 heterojunction composite photocatalysts for augmented charge separation and photocatalytic degradation performance with superior antibacterial activity

The development of advanced photocatalysts is critical for addressing environmental pollution and enhancing water purification processes. Our study has effectively developed a novel MnO2/g-C3N4 (MGC) heterojunction composite photocatalyst exhibiting superior photo-degradation under visible-light (VL) conditions and also established antibacterial activities. Comprehensive characterization was acquired using XRD, FT-IR, FE-SEM with EDX-associated mapping images, TEM, UV–Vis DRS and PL investigations, indicating the successful formation of well-dispersed MnO2 nanoparticles (NPs) over the g-C3N4 catalyst. The MGC composite heterojunction photocatalyst demonstrated increased photocatalytic degradation activity of 77.2 % in aqueous crystal violet (CV) under VL within 120 min, significantly outperforming pure g-C3N4 and MnO2 by 3.02 and 2.37 times, respectively. The MGC composite demonstrates remarkable stability and reusability, retaining 73.7 % of its efficiency after five consecutive cycles. Additionally, the as-synthesised composite endows potent antibacterial action against various pathogenic bacteria including K. pneumonia, S. aureus, E. coli and B. cereus. The active species analysis indicates that the composite photocatalyst facilitates charge transfer, while effectively preventing the recombination of photo-produced carriers via an effective Z-scheme mechanism, and the synergistic things among MnO2 and g-C3N4 are accredited to the boosted photocatalytic and antibacterial activities. This research describes a photocatalytic approach for efficiently eliminating various contaminants from water bodies, which has significant implications for the future development of photocatalytic technology for wastewater handling.

Z-scheme CoWO4/g-C3N4 heterojunction for enhanced ultraviolet-light-driven photocatalytic activity towards the degradation of tetracycline

Z-scheme CoWO4/g-C3N4 heterojunction for enhanced ultraviolet-light-driven photocatalytic activity towards the degradation of tetracycline

Construction of (001)-TiO2/g-C3N4 heterojunction for enhanced photocatalytic degradation of methylene blue

Construction of (001)-TiO2/g-C3N4 heterojunction for enhanced photocatalytic degradation of methylene blue

High-efficiency and stable Z-scheme heterojunction of Co9S8 anchored by g-C3N4 for peroxymonosulfate activation

Photocatalytic technology and peroxymonosulfate (PMS) based advanced oxidation technology have been proven to be simple and effective strategies for recalcitrant organic pollutants degradation. In this work, we designed and prepared a coupled photocatalytic and advanced oxidation system for sulfamethazine (SMR) antibiotics degradation. Firstly, a series of Z-scheme Co9S8/g-C3N4 heterojunction photocatalysts are prepared by a simple two-step method and further work as PMS activators. The prepared Co9S8/g-C3N4 photocatalysts exhibit a great improvement in electron-hole pairs migration and visible-light response due to heterojunction formation. In addition, the g-C3N4 acts as a substrate to anchor the Co9S8 nanoparticle, which suppresses the Co9S8 leaching and prevents the Co9S8 oxidation. Consequently, the Co9S8/g-C3N4/PMS system displayed an improved SMR degradation ability (93 % for Co9S8/g-C3N4/PMS vs. 86 % for Co9S8/g-C3N4). After the fourth cyclic degradation experiment, the Co9S8/g-C3N4/PMS system still maintained a comparatively high degradation rate. Considering its good properties and better degradation performance, we propose that the synergistic effect of photocatalytic technology and PMS possess a promising prospect for application in environmental treatment.

Construction of Ag-modified ZnO/g-C3N4 heterostructure for enhanced photocatalysis performance.

ZnO/g-C3N4 heterojunction modified with Ag nanoparticles (ZnO/CN/Ag) was synthesized by depositing ZnO nanorods/Ag nanoparticles onto g-C3N4 nanosheets. Under xenon lamp irradiation, 99% of Rhodamine B (RhB) was degraded by ZnO/CN/Ag-5% composite within 30min, which was much higher than the degradation efficiency of ZnO and ZnO/CN. The synergistic effect of g-C3N4 and ZnO, along with the localized surface plasmon resonance effect of Ag NPs, contributes to the improvement of photocatalytic performance. Ag nanoparticle provides another charge transfer path from g-C3N4 to ZnO, which speeds up the separation of electron-hole pairs. Meanwhile, the catalyst had good stability and recyclability. Finite-difference time-domain method and the density functional theory were used to obtain the charge transfer process. The photodegradation process has been studied in depth.

Sonochemical preparation of powerful S-scheme Zr(HPO4)2/g-C3N4 heterojunction for photocatalytic degradation of rhodamine B under natural solar radiations

An effective Zr(HPO4)2/g-C3N4 S-scheme heterojunction was synthesized by sonochemical coupling of Zr(HPO4)2 nanoparticles as an oxidative photocatalyst [EVB = +3.0 eV] with g-C3N4 nanosheets as an effective reductive photocatalyst [ECB = −1.25 eV] for photocatalytic degradation of rhodamine B dye under natural solar radiation of 1000 W power. The physicochemical properties of the as-synthesized heterojunctions were investigated by X-ray diffraction [XRD], N2-adsorption-desorption isotherm, diffuse reflectance spectrum [DRS], photoluminescence [PL], scanning electron microscope [SEM], X-ray photoelectron spectroscope [XPS], and high resolution transmission electron microscope [HRTEM]. The experimental results implied the agglomeration of Zr(HPO4)2 nanoparticles on g-C3N4 sheets which reduced the specific surface area of the solid specimen from 88 to 21 m2/g. The significant increase in the photocatalytic degradation rate of RhB dye with introducing Zr(HPO4)2 nanoparticles implied that Zr(HPO4)2 plays a crucial role in reducing the band gap energy and remarkable increasing in the rate of electron-hole separation. The photocatalytic experiments implied that incorporation of 5 wt% Zr(HPO4)2 on g-C3N4 sheets destroyed 98 % of RhB dye during 3 h of light illumination with pseudo-first-order rate of 0.048 min−1. The remarkable enhancement in the photocatalytic performance of Zr(HPO4)2/g-C3N4 heterojunctions was ascribed to successful generation of an effective S-scheme heterojunction with strong redox power, utilizing of both hydroxyl and superoxide radicals in the degradation process and limiting the electron-hole recombination rate. Based on scavenger experiments and terephthalic acid PL analysis, the S-scheme pathway was chosen as the proposed mechanism for photocatalytic charge transfer. The as-synthesized Zr(HPO4)2/g-C3N4 heterojunction with exceptional redox power is considered a novel candidate for destructing organic pollutants that exist in industrial wastewater.

Construction of BaTiO3/g-C3N4 heterojunction for promoting atrazine degradation of hydraulic-driven piezocatalytic ozonation

Catalytic ozonation, as a popular water purification technology, was restrained with the dilemma of slow Me(n+m)+/Men+ redox cycle of the convention catalysts. To this end, BaTiO3/g-C3N4 (BTO/CN) piezoelectric heterojunction was designed to enhance atrazine (ATZ) degradation in piezocatalytic ozonation, utilizing the overlooked mechanical forces to activate O3 into reactive oxygen species (ROS). Characterization results demonstrated that the couple of BTO and CN successfully formed a Type-II heterojunction, enhancing the separation of piezoelectric carriers (e- and h+). Moreover, BTO/CN showed the better O3 affinity and O3 activation capability over that of BTO and CN. BTO/CN/O3 process achieved 90.1 % ATZ removal, which was 3.5 and 1.7 times over that of the BTO/O3 and CN/O3 processes, respectively. ATZ removal in BTO/CN/O3 process increased with the initial pH value. Cl-, SO42- and NO3- inhibited ATZ removal, but HCO3- enhanced ATZ removal. O3, •OH, O2- and 1O2 were all involved in ATZ degradation and •OH served as the main ROS, accounting for 79.3 % in degrading ATZ. The internal electric field along with the interfacial electric field synergistically boosted the separation and transfer of charge carriers to provide e- for O3 activation and ROS generation. This study broke through the basic need of continuous sacrifice of e- for O3 activation induced by metal redox cycle and provided a novel catalyst design strategy for piezoelectric ozonation.

Light switchable radical and non-radical periodate activation by Fe3O4/g-C3N4 for efficient organic contaminant elimination

Although the heterogeneous activation of periodate (PI) has recently garnered significant attention for organic pollutant degradation, regulating the non-radical and radical reaction pathways remains a challenge. Herein, a Z-scheme Fe3O4/g-C3N4 heterojunction (FCN) was developed to achieve controllable radical and non-radical PI activation using a light switch. In the dark, the interaction between FCN and PI gave rise to metastable surface-activated PI complexes (PI*) via the non-radical pathway, which served as the dominant reactive species for organic elimination. Upon light irradiation, FCN acted as an electron donor for PI activation via the radical pathway, forming iodate radicals (IO3•) for pollutant destruction. Consequently, the FCN/PI/VIS system achieved complete removal of acid orange 7 in 30 min, with a pseudo-first order reaction rate about 3.5 times higher than that of FCN/PI system. The involved reactive species were validated by scavenging tests, electron paramagnetic resonance (EPR) analysis, Raman spectra and electrochemical measurements. Moreover, the light switchable FCN-based PI activation system exhibited high recyclability and practicability for the treatment of various organic pollutants in water. This study provides new insights into the PI activation-mediated wastewater treatment processes.

In-Situ Construction of Atomic-Level Fe-O Bond Bridges within Fe2N/g-C3N4 Heterojunction for Efficient Visible-Light-Driven Photocatalytic H2 Production.

The limited active sites and faster photogenerated electron-hole pair recombination rate of g-C3N4 restrict its application in photocatalytic H2 production. Constructing heterojunctions has been shown to improve the spatial (directional) separation of photogenerated electrons and holes. However, due to interface mismatch in traditional heterojunction structures and a lack of precise electron transport channels, the photocatalytic efficiency is limited. Here, we developed a two-step calcination approach to create an Fe2N/g-C3N4 heterojunction linked by Fe-O bonds (named as Fe-OCN). The newly formed Fe-O bonds within the heterojunction can act as atomic-level interface electron transfer channels, directly transferring the photogenerated electrons of g-C3N4 to the reactive center Fe2N, significantly improving the charge transfer rate and utilization, thus promoting visible-light-driven photocatalytic H2 production. The optimal Fe-OCN achieved a H2 production rate of 5986.29 μmol g-1 h-1 under visible light, 13.44 times higher than that of the OCN due to efficient charge separation and transfer capabilities. This work provides a constructive reference for the design and synthesis of organic-inorganic heterojunction with chemically bonded interfaces, establishing quick electron transfer channels, and achieving targeted electron transfer.

Photoirradiation-enhanced behavior via morphological manipulation of CoFe2O4/g-C3N4 heterojunction for supercapacitor and CO2 reduction

Regulating the morphology of graphitic carbon nitride (g-C3N4, CN) and constructing CoFe2O4/g-C3N4 (CFO/CN) heterojunctions were adopted in the photocatalytic energy storage and photocatalytic CO2 reduction (PCR). CFO/CNS had outstanding light response ability, while CFO/CNT possessed excellent charge transfer ability. Consequently, CFO/CNT electrode exhibited the highest specific capacitance without light, CFO/CNS electrode showed the most obvious photo-enhanced capacitance behavior with an increase by 21.05 % under light. This was ascribed to the generation and separation of photo-generated carriers, promoting oxidation/reduction reactions. And in PCR, the electron consumption rates of four CFO/CN heterojunctions were CFO/CNT > CFO/BCN > CFO/MCN > CFO/CNS. CFO/CNT presented the highest photocatalytic activity, attributing to the strong redox ability and photo-enhanced electron transfer. This strategy of utilizing CFO/CN heterojunctions to construct photo-enhanced supercapacitor electrodes and photocatalytic CO2 reduction catalysts provided new ideas for energy conversion and storage.

Oxygen Vacancies Regulated S-Scheme Charge Transport Route in BiVO4-OVs/g-C3N4 Heterojunction for Enhanced Photocatalytic Performance.

Oxygen vacancies (OVs) are widely considered as active sites in photocatalytic reactions, yet the crucial role of OVs in S-scheme heterojunction photocatalysts requires deeper understanding. In this work, OVs at hetero-interface regulated S-scheme BiVO4-OVs/g-C3N4 photocatalysts are constructed. The Fermi-level structures of BiVO4 and g-C3N4 lead to a redistribution of charges at the heterojunction interface, inducing an internal electric field at the interface, which tends to promote the recombination of photogenerated carriers at the interface. Importantly, the introduction of OVs induces defect electronic states in the BiVO4 bandgap, creating indirect recombination energy level that serves as crucial intermediator for photogenerated carrier recombination in the S-scheme heterojunction. As a result, the photocatalytic degradation rate on Rhodamine B (RhB) and tetracyclines (TCs) for the optimal sample is 10.7 and 11.8 times higher than the bare one, the photocatalytic hydrogen production rate is also improved to 558 µmol g-1 h-1. This work shows the importance of OVs in heterostructure photocatalysis from both thermodynamic and kinetic aspects and may provide new insight into the rational design of S-scheme photocatalysts.

Efficient photocatalytic CO2 and Cr(VI) reduction on carbon quantum dots/carbon nitride heterojunctions

Carbon quantum dots (CQDs), known for their exceptional optical properties, hold the potential to enhance light absorption, charges separation and transfer in semiconductor materials. However, using cheap medicinal materials as precursors in the field of photocatalysis to obtain CQDs has seldom concerned. In this study, we utilized biomass-derived CQDs from carbon-rich licorice powder to improve photocatalytic CO2 and Cr(VI) reduction in polymer carbon nitride (PCN). The CQDs/g-C3N4 heterojunctions were synthesized via a hydrothermal method, and the successful fabrication and integration of CQDs on g-C3N4 surfaces were confirmed through detailed characterization. The optimal sample with a licorice powder to PCN mass ratio of 0.05:1 ((50CQDs/CN) demonstrates a tripling in CO2 conversion efficiency under simulated sunlight compared to the reference PCN. Under visible light irradiation, the 50CQDs/CN also performs superior photocatalytic Cr (VI) removal efficiency, which is 2.48 times of that of the reference PCN. This significant boost is attributable to the successful construction of the CQDs/CN heterojunction and the abundance of functional groups on the CQDs surface, which provide more active sites, improve light absorption and increase charges migration rates. The stability of these new photocatalysts was confirmed through repeated photocatalytic cycles, indicating their potential for practical applications. Mechanistic studies reveal insights into the enhanced photocatalytic pathways and intermediate conversion processes. Our findings present a novel, efficient and sustainable route to fabricate g-C3N4-based photocatalysts, offering a promising strategy for further mitigate the greenhouse gas crisis and environmental pollution.

Multipath collaboration-based signal amplification on Z-scheme In2O3/g-C3N4 heterojunction photoelectrode for sensitive photoelectrochemical immunoassay

The ideal photoelectrode and efficient signaling strategy are pivotal to achieve sensitive photoelectrochemical (PEC) analysis. Here, a multipath collaborative signal amplification-based PEC immunosensor was constructed for the ultrasensitive detection of cytokeratin 19 fragment 21-1. Specifically, the photoelectrode fabricated by Z-scheme In2O3/g-C3N4 heterojunction showed enhanced photocurrent intensity in response to visible light. Meanwhile, the signal probe, horseradish peroxidase functionalized dopamine-melanin nanosphere@Au nanoparticles (HRP-Dpa-melanin NS@AuNPs), were introduced into the system. When the target exists, the signal probe can induce multiple quenching of the photocurrent due to the competition of light absorption, steric hindrance and HRP-mediated biocatalytic precipitation, which effectively inhibit light, electron donor, and electron access to the photoelectrode. The fabricated immunosensor exhibits a wide linear range from 1.0 × 10−3 - 1.0 × 102 ng mL−1 with the detection limit of 0.35 pg mL−1 (S/N = 3) for cytokeratin 19 fragment 21-1 detection. The study enhances sensitivity for PEC detection by utilizing the superior Z-scheme heterojunction photoelectrode, providing a valuable method that combines multiple signal pathways for a synergistic effect in bioanalysis.

Polyacid-Modulated Carrier Dynamic Behavior at the Interface of 0D/2D Heterojunctions.

Heterojunctions formed by polyoxometalates and 2D materials draw attention owing to their remarkable photoelectric and catalytic properties. However, the intrinsic mechanisms of polyoxometalates regulating the heterojunction photoelectric properties are unclear. Herein, we constructed two types of heterojunctions by integrating polyoxometalates (Keggin-type H3PW12O40 and Lindqvist-type H2W6O19) on g-C3N4 monolayers, exploring photoexcited carrier dynamics in these heterojunctions by ab initio calculations combined with nonadiabatic molecular dynamics (NAMD) simulations. Our results show that electrons and holes in H3PW12O40 on g-C3N4 monolayers relax within 583 and 760 fs, respectively. The electron-hole recombination occurs at 342 fs, faster than carrier separation, aligning with the behavior of Z-type heterojunctions. Contrarily, the H2W6O19/g-C3N4 heterojunction exhibits the typical characteristics of type II heterojunctions, with a long photogenerated carrier lifetime reaching 652 fs. These findings show tunable band alignment in polyoxometalate-supported systems by modulating polyoxometalate type, influencing hot electron dynamics, and guiding 0D/2D heterojunction design.

Nitrogen-oxygen defect engineering enhanced intrinsic electric field in CoFe2O4/g-C3N4 heterojunctions for photocatalytic tetracycline degradation and H2 evolution

A range of efficient g-C3N4/CoFe2O4 heterojunction with nitrogen deficiencies (NDs) and oxygen deficiencies (ODs) were successfully synthesized through doping-melting and hydrothermal methods. Nitrogen-oxygen defect engineering effectively enhanced the active sites on the catalyst surface and regulated the optical bandgap, band structure, and work function (Φ) of g-C3N4 and CoFe2O4, regulating the strength of the intrinsic electric field (IEF) and promoting the separation of photo-generated carriers at the heterojunction interface. Among the series of samples, CH-H2@CFO-A5 (properly oxalate-doped g-C3N4/CoFe2O4 heterojunctions treated with prolonged annealing) demonstrated remarkable optical properties due to its narrowest optical band gap, while the strongest IEF and redox potential make it has strong carrier dynamics and photocatalytic efficiency. Under visible light, the mineralization rate of tetracycline (TC) on CH-H2@CFO-A5 and the photocatalytic hydrogen production rate were 4.51 times and 2.72 times higher than that of unmodified CN-H0@CFO-A1, respectively. This study aimed to provide an efficient strategy for regulating the IEF within the heterojunction, by altering the Fermi level through multi-element defect engineering.

High-capacity and high-stability capacitive desalination with dual redox-active MnCo2S4/g-C3N4 heterojunction electrode

Capacitive deionization (CDI) utilizing dual redox-active electrodes has shown significant promise in desalinating low-concentration brackish waters, which is crucial for addressing global freshwater shortages. However, improvements in salt adsorption capacity and long-term operational stability are still required. In this study, we introduce, for the first time, a binary metal sulfide MnCo2S4/g-C3N4 (MCS-CN) heterojunction as a CDI electrode. The innovative integration of dual redox-active centers and heterojunction structures in the MCS-CN composite electrodes underscores their potential for achieving both high capacity and stability in capacitive desalination applications. The microscopic morphology, crystal structure, pore structure, and surface valence properties of the MCS-CN heterojunction composite materials were extensively characterized using various analytical techniques. In-situ X-ray diffraction, refined ex-situ X-ray photoelectron spectroscopy, three-electrode electrochemical analysis, and theoretical calculations were employed to elucidate the electrosorption and desorption mechanisms of sodium ions with the MCS-CN electrodes and to clarify the enhanced desalination performance of the binary metal sulfide-based heterojunction structure. As a result, the optimal MCS-CN-40 electrode exhibited the highest salt removal capacity of 71.64 mg g−1 and maintained stable desalination performance over 100 cycles in a 500 mg L−1 NaCl solution. This innovative approach provides a noval perspective for developing heterojunction electrodes with high redox activity and efficient desalination performance.

Facile construction of ZnWO4/g-C3N4 heterojunction for the improved photocatalytic degradation of MB, RhB and mixed dyes

This study presents the construction of binary ZnWO4/g-C3N4 nanocomposite via a facile hydrothermal approach to enhance the photocatalytic performance under the visible light irradiation. The proposed ZnWO4/g-C3N4 nanocomposite photocatalyst shows excellent photodegradation towards organic dyes, such as methylene blue (MB) and rhodamine B (RhB). The optimal loading of ZnWO4 and g-C3N4 leads to the synergistic effect which plays a predominant role in inhibiting the fast electron-hole pairs recombination rate at the interface of ZnWO4/g-C3N4 photocatalyst. The degradation rates of MB and RhB is achieved around 92.9 % and 88.8 % under the visible light irradiation for 120 min. According to our findings, the radical quenching experiments suggested that the ●OH radicals played a positive impact in the photodegradation process. Since, our proposed photocatalyst exhibit superior photocatalytic activity towards the individual MB and RhB degradation. The ZnWO4/g-C3N4 photocatalyst were further applied to demonstrate the degradation of mixed dyes (MB and RhB) at an irradiation time of 180 min. In the mixed dye solution, the ZnWO4/g-C3N4 photocatalyst achieved a highest reaction rate of 0.010 min−1 for MB and 0.012 min−1 for RhB with the degradation rate of 87.8 % and 83.3 % for RhB and MB, respectively. For the mixed dyes, the radical quenching experiments confirmed that the ●OH radicals are responsible for the fast photodegradation. Additionally, the practicality of the proposed ZnWO4/g-C3N4 photocatalyst towards the degradation of MB, RhB and the mixed dyes were examined in the tap water samples. Furthermore, the plausible photodegradation mechanism of ZnWO4/g-C3N4 photocatalyst was proposed in detail. This study provides a new insight for the simultaneous degradation of mixed chemical pollutants using our proposed ZnWO4/g-C3N4 photocatalyst.

Combining rhombohedral dodecahedral ZnO with g-C3N4 nanosheets for enhanced photocatalytic activity

Photocatalysis technology is an effective method to remove pollutants in aquatic environment assisted by solar energy. Herein, the rhombohedral dodecahedral ZnO was dispersed on the g-C3N4 nanosheets for the construction of ZnO/g-C3N4 heterojunction via the combination of solvothermal method and calcination. The obtained ZnO/g-C3N4 heterojunction manifests excellent photocatalytic ability for methyl orange (MO). Especially, the optimal ZnO/g-C3N4 composite with the ZnO content of 10 wt% (ZC-3) exhibits the degradation efficiency of MO as high as 98.0% under visible-light of 60 min. A series of factors were all-around investigated, such as initial pH, photocatalyst dosage, initial MO concentration, organic anions, humic acid and other dyes. The photocatalytic degradation behavior of MO complies with the first-order reaction kinetics, and the apparent rate constant (kapp) of ZC-3 is 2.3 and 13.4 times than that of pure g-C3N4 and pure ZnO. Meanwhile, the ZnO/g-C3N4 heterojunction exhibits satisfactory cyclic stability and its photocatalytic mechanism is postulated. Therefore, the ZnO/g-C3N4 heterojunction possesses great economic utilization value and is expected to be widely used for wastewater remediation.