Photodegradation Of Methylene Blue Research Articles

Metal–organic framework derived N‐doped zinc oxide carbon nanocomposites for catalytic removal of dye and formaldehyde

AbstractBiomass‐based catalysis has drawn a gradually increased attention due to its eco‐friendliness, cost‐effective, and good reusability. In this work, a novel metal–organic framework (MOF) derived nitrogen‐doped zinc oxide carbon (ZnO/N/C) nanocomposites were synthesized on pine cone by solvothermal and carbonization method. Scanning electron microscopy, x‐ray diffractometer, and x‐ray photoelectron spectroscopy were employed to confirm the presence of N‐doped ZnO rod‐like nanostructures on the as‐prepared composites. The obtained ZnO/N/C nanocomposites were employed as catalytic materials for the decomposition of methylene blue (MB) dye and adsorption of formaldehyde (HCHO). The ZnO/N/C nanocomposites can degrade more than 90% of the MB solution within 90 min under visible light irradiation, besides, they can rapidly absorb and decompose HCHO. The high‐catalytic performance of ZnO/N/C nanocomposites can be attributed to the high‐superficial area of ZIF‐8, the carbonization that ensures the high conductivity and high‐slight absorption of carbon skeleton materials, and the accelerated transfer of photogenerated electrons. This simple and green preparation method has promoted the sustainable utilization of biomass resources with great significance for application of carbon‐based porous materials in catalytic field.Highlights MOF derived ZnO/N‐doped carbon nanocomposites were successfully synthesized. Presence of N‐doped ZnO rod‐like nanostructures on carbon nanocomposites. ZnO/N/C nanocomposites could be used as a catalyst for MB photodegradation. ZnO/N/C nanocomposites can be readily absorption and decompose of HCHO.

Insight into the novel ZIF-8@N-CQDs/ZIF-67 nanocomposite for photocatalytic degradation of methylene blue under visible light irradiation

A novel and stable composite of ZIF-8@N-CQDs/ZIF-67 was synthesized using simple solvothermal methods. The structural and morphological properties of the composite were investigated using different techniques. The ability of N-CQDs to improve the photocatalytic activity of ZIF-8@ZIF-67 for the photodegradation of methylene blue (MB) using visible and solar light was tested.The composite exhibited higher light adsorption and charge separation capabilities than N-CQDs and ZIF-8@ZIF-67. The degradation % of 32.0 ppm MB under visible light irradiation reached 94.0 % after 180 min, and the composite maintained its photoactivity after four cycles with a minimal decrease in the degradation efficiency.Scavenging tests indicated that the free electrons (superoxide radicals) played a major role in the photodegradation of MB, which is followed by hydroxyl radicals and holes. Therefore, this work provides a new, stable, environmentally friendly, and highly effective photocatalyst for the treatment of various organic pollutants under visible light irradiation.

Optimizing physical properties of BiFe1-xMnxO3 perovskite thin films via a low-temperature sol-gel method

Multiferroic materials have recently attracted great attention for possible use in photovoltaic and photocatalytic devices. In this study, pure-phase BiFe1-xMnxO3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) thin films were deposited on glass substrates via low-temperature sol-gel assisted spin coating procedure. We found that the thin films undergo a rhombohedral to cubic structural transition. From FESEM images, it was observed that different amount of Mn affects the surface morphology and grain size of the studied samples. For all samples, the absorption coefficient was in the range of 105 cm−1, and the refractive index and extinction coefficient of samples were about 1.15–1.50 and 0.2–0.9, respectively. BiFe0.8Mn0.2O3 thin film has the lowest bandgap energy due to the highest absorption coefficient at the wavelengths of 400–1100 nm denoted by its lowest transmittance. Structural and magnetic results show the substitution of low-spin smaller Mn ions for high-spin larger Fe ions. The best photocatalytic activity was observed for BiFe0.8Mn0.2O3 thin film with a removal efficiency of 78.83% in the photodegradation of methylene blue.

Improved charge transport kinetics in PbBi2Nb2O9 photocatalysts: Comparative time-resolved recombination study with N-doped TiO2

(100) layered Aurivillius-phase perovskite single-phase PbBi2Nb2O9 (PBNO) photocatalyst was reported to be an efficient photocatalyst as compared to the conventionally known visible light photocatalyst of N doped TiO2 (NTO). We report here the specific photoluminescence studies of PBNO to understand its improved photocatalytic property. We have synthesized PBNO and NTO photocatalyst films. Further, their structural, optical and photocatalytic degradation properties have been studied. PBNO demonstrated superior methylene blue degradation as compared to NTO, under visible light photons. The steady-state and time-resolved photoluminescence (PL) studies were specially utilized at characterization tool to understand reason of the high photocatalytic activity of PBNO. We analyzed how high crystallinity of PBNO, and the longer recombination lifetime due to charge separation during photocatalytic reaction yields improved activity in PBNO as compared to NTO. Accordingly, mechanistic scheme for methylene blue photodegradation under solar light photons has been proposed. This study also indicates importance of photoluminescence study for photocatalysts.

Photo(electro)catalytic Performance of ZnO‐Based Nanopowders Prepared through Pulse Alternating Current Electrosynthesis in Alkaline Earth Chloride Electrolytes

AbstractPhoto(electro)catalysis is a technology that allows abundant and clean solar energy to be harvested as an essential step to achieving sustainable development goals. However, controllable and economically viable synthesis of nanocatalysts is one of the key challenges that hinder the practical application of many important energy‐related photo(electro)catalytic reactions. In this study insights into the electrosynthesis of ZnO‐based materials using pulse alternating current as a green oxidant and the alkaline earth metal chloride aqueous solutions as electrolytes were provided. The effect of electrolyte on composition and structure of final products was demonstrated. ZnO photocatalyst prepared in BaCl2 exhibited different activity tendency in photoelectrocatalytic and photocatalytic systems showing the highest photocurrent (0.18 mA cm−2) for ZnO photoelectrode annealed at 300 °C and maximum rate constant for methylene blue dye photodegradation in the presence of ZnO particles annealed at 500 °C. Optimized ZnO nanopowder was further employed for the degradation of 2,4‐dinitrophenol pollutant in a custom‐designed flow photoreactor operating under low‐power UV. 2,4‐dinitrophenol was degraded to 90.1 % at ZnO dosage of 0.2 mg L−1 within 280 min of illumination. Overall, the optimization of pulse alternating current electrosynthesis and post‐annealing might be promising and sustainable approach to ZnO‐based nanopowders for environmental photo(electro)catalytic applications.

A study on the applicability of thin film over powder for visible light photocatalysis

Copper oxide nanoparticles (CuO-NPs) powder and copper oxide thin films (CuO-TFs) have been studied to reveal their applicability in photodegradation. The CuO-TFs are found to be better photocatalysts as compared to powder form in the photodegradation of methylene blue (MB) dye solution. The photocatalytic effect of CuO-TFs (0.83 mg of deposited CuO), CuO-NPs powder (0.83 mg), and self-degradation of MB dye solution are found to be 83.91%, 52.40%, and 25.8% respectively. The FESEM images reveal that CuO-NPs are more prone to agglomeration than CuO-TFs. The average particle size of CuO-NPs and CuO-TFs are found to be 6.90 nm and 6.07 nm respectively. XPS analysis reveals lesser oxygen defects in CuO-TFs, which results in higher MB photodegradation activity as compared to CuO-NPs. The specific surface area of CuO-NPs and CuO-TFs are found to be 33.714 m2/g and 20.668 m2/g. The easy reusability and photocatalytic performance manifest CuO-TFs as better photocatalysts.

Black sand as a cost-effective catalyst for methylene blue photo-remediation under visible light

Methylene blue (MB) is commonly a persistent and perilous pollutant in industrial wastewater effluent. While MB has a massive negative effect on human and ecology safety. The neutralization of such harmful material would save a huge clean water amount. This work proposes the natural and abundant black sand as a catalyst for MB photodegradation. The sand sample was calcined at three temperatures of 300°, 400°, and 600 °C. The properties of samples were analyzed with different micro- as well as spectroscopic techniques. The experimental data revealed the sample's main composition of SiO2, Fe2O3, and Al2O3. XRD and XPS results proved the formation of mixed oxides composites due to calcination, especially at 400 °C. The UV–vis analysis conducted showed that samples can absorb light in the visible range. The photodegradation reached a maximum of 975.3%, 82.7%, and 75.7% for BS400, BS600, and BS300 respectively; by illumination for 2.5 h in the visible range. The observed distinguishable catalytic performance was discussed via the spectroscopic analysis and oxygen availability in the catalyst lattice. When AO, t-BuOH, and BQ are used as scavengers instead of just BQ during the photodegradation of MB dye over BS400 catalyst, the photodegradation rate drops significantly. The degradation % of MB dye diminished to 60%, and 70% by using AO, t-BuOH, and BQ scavengers; respectively. This proved that rather than hydroxyl radicals, superoxide radicals or positive hole production is the main determining step in MB photo-degradation over BS400 catalyst.

Highly Efficient SnIn4S8@ZnO Z-Scheme Heterojunction Photocatalyst for Methylene Blue Photodegradation.

Building heterojunctions is a promising strategy for the achievement of highly efficient photocatalysis. Herein, a novel SnIn4S8@ZnO Z-scheme heterostructure with a tight contact interface was successfully constructed using a convenient two-step hydrothermal approach. The phase composition, morphology, specific surface area, as well as photophysical characteristics of SnIn4S8@ZnO were investigated through a series of characterization methods, respectively. Methylene blue (MB) was chosen as the target contaminant for photocatalytic degradation. In addition, the degradation process was fitted with pseudo-first-order kinetics. The as-prepared SnIn4S8@ZnO heterojunctions displayed excellent photocatalytic activities toward MB degradation. The optimized sample (ZS800), in which the molar ratio of ZnO to SnIn4S8 was 800, displayed the highest photodegradation efficiency toward MB (91%) after 20 min. Furthermore, the apparent rate constant of MB photodegradation using ZS800 (0.121 min-1) was 2.2 times that using ZnO (0.054 min-1). The improvement in photocatalytic activity could be ascribed to the efficient spatial separation of photoinduced charge carriers through a Z-scheme heterojunction with an intimate contact interface. The results in this paper bring a novel insight into constructing excellent ZnO-based photocatalytic systems for wastewater purification.

Controllable Synthesis, Photocatalytic Property, and Mechanism of a Novel POM-Based Direct Z-Scheme Nano-Heterojunction α-Fe2O3/P2Mo18.

In order to improve photocatalytic activity and maximize solar energy use, a new composite material Fe2O3/P2Mo18 was prepared by combining polyoxometalates (P2Mo18) with Fe2O3 nanosheets. FT-IR, XRD, XPS, SEM, TEM, UV-vis, EIS, and PL were used to characterize the composite material, and nano-Fe2O3 of different sizes and morphologies with a controllable absorption range was prepared by adjusting the reaction time, and, when combined with P2Mo18, a composite photocatalyst with efficient visible light response and photocatalytic activity was constructed. The EIS, Bode, and PL spectra analysis results show that the Fe2O3/P2Mo18 composite material has outstanding interfacial charge transfer efficiency and potential photocatalytic application possibilities. Model reactions of methylene blue (MB) and Cr (VI) photodegradation were used to evaluate the redox activity of Fe2O3/P2Mo18 composites under simulated visible light. The photocatalytic degradation rate was as high as 98.98% for MB and 96.86% for Cr (VI) when the composite ratio was Fe2O3/P2Mo18-5%. This research opens up a new avenue for the development of high-performance photocatalysts.

Design of Ag@ZnO@Ti3C2 MXene heterojunction photocatalyst for enhanced photocatalytic degradation activity of methylene blue and levofloxacin under visible light irradiation

A ternary Ag@ZnO@Ti3C2 MXene heterojunction (AZM) is synthesized by hybridizing ZnO and Ag nanoparticles with the MXene via a simple hydrothermal and chemical deposition method. The addition of ZnO and Ag can effectively compensate for MXene’s narrow bandgap property, promote charge carrier separation, and improve visible light absorption, thereby enhancing photocatalytic activity. The photocatalytic activity of the AZM is evaluated through the removal efficiency of methylene blue (MB) dye and levofloxacin (LVX) under visible light irradiation. The results show that the optimized ternary AZM heterojunction photocatalysts (AZM-15) possesses the maximum degradation of MB (90.54%) with a reaction rate constant of 0.0473 min−1, while the maximum degradation of LVX (86.76%) has a reaction rate constant of 0.0408 min−1. Moreover, the AZM composite exhibits excellent stability, which explains its MB removal rate of 83.59% and LVX removal rate of 80.03% after five cycles. The results of trapping experiments and EPR demonstrated that the main active species in the MB and LVX photodegradation process are·OH and·O2-. This work not only elucidates a possible mechanism of photocatalytic degradation of organic pollutants but also provides a pathway to design new bandgap photocatalysts for mitigating environmental pollution.

A Zn-based Zig-Zag 1D chain type coordination polymer for removal of methylene blue dye from an aqueous solution

A 1D zig-zag zinc coordination chain, [Zn(piv)2]n (1) (where piv = pivalic acid) has been synthesized by a reaction of ZnCl2 with O-donor pivalic acid in the mixed solvent system (MeCN/MeOH) and structurally characterized via ultraviolet–visible spectroscopy (UV), Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, and X-ray crystallography. The crystal structure is a bridging chain of zinc metal connected via pivalic acids. The synthesized coordination polymer was explored for photochemistry to study photoluminescence and photocatalytic properties. The photocatalytic properties were investigated against methylene blue (MB) dye under UV light illumination. Under optimal reaction conditions (catalyst dosage = 10 mg, initial concentration of dye = 20 mg/L, pH = 9) the maximum photodegradation of methylene blue was found to be 72.56% in 120 min illumination time. The photocatalytic reaction showed pseudo-second-order kinetics with a rate constant of 0.012 L.mg−1.min−1. Furthermore, the recyclability test showed that compound 1 retained its photocatalytic potential even after five successive uses. The compound 1 could be a proficient and economical choice for the photocatalytic elimination of pollutants from wastewater.

The role of Ni-Doped ZnO thin films on Methylene Blue (MB) photodegradation under visible irradiation

We report the effect of Ni-doped ZnO thin films on the photodegradation of methylene blue (MB) under visible irradiation. The Ni-doped ZnO thin films were deposited on a silicon substrate by ultrasonic spray pyrolysis (USP) at 450 °C for 15 minutes. The ZnO thin films are characterized by X-ray diffraction (XRD) and UV-Vis spectroscopy. The X-ray diffraction (XRD) pattern for all samples confirms that the crystalline phase of Ni-doped ZnO thin films is polycrystalline hexagonal wurtzite. However, due to the Ni incorporation into the ZnO site, there is a change in the crystal plane. All ZnO films confirmed photocatalytic properties, indicating methylene blue (MB) degradation under visible irradiation. Nevertheless, the degradation of the MB dye increased by about 76% with increasing Ni incorporation. Therefore, we confirmed that Ni incorporation affects the photocatalytic properties of the ZnO thin films.

Correction to: Facile fabrication of CoAl2O4 based grow nanohybrid as an environmental purifier for photodegradation of methylene blue

Correction to: Facile fabrication of CoAl2O4 based grow nanohybrid as an environmental purifier for photodegradation of methylene blue

Nanoplasmonic engineering construction of europium oxide incorporated on graphene oxide surface and its nano heterojunction through the zinc oxide nanoparticles for water-clean

The redesigned engineering building of europium (III) oxide nanoparticles and zinc oxide nanoparticles on the electron carrier surface of graphene oxide nanosheet is the main target to increase the effectiveness of the electron transfer and photogeneration of reactive oxygen species for the photocatalytic and adsorption process. The hybrid nanocomposite fabricates by the precipitation and grinding method and characterization of the nanocomposite perform by various techniques, such as field emission scanning electron microscopy (FEG-SEM), FT-IR spectroscopy, zeta potential, and UV–visible spectrophotometer. The hybrid nanocomposite's stability is performed through the cyclic voltammetry technique by measuring the CV-cycle's multi-cycles. The adsorption process and photocatalytic activity are detected by using the UV–visible spectroscopy, where the degradation efficiency of characterized absorption peaks of pollutants was followed. The ability of the modified surface of hybrid nanocomposite against the pollutants for example methylene blue dye, p-nitrocatechol, p-nitrophenol, and removal of the chromium heavy metal to obtain the clean water was performed successfully. The rate constant and efficiency of the fabricated nanocatalyst were calculated, the photodegradation of methylene blue was 0.005 min−1 (efficiency 68 %), in sodium hydroxide was 0.03764 min−1 (efficiency 94 %), and in hydrogen peroxide was 0.02837 min−1 (efficiency 96 %). The p-nitrocatechol has photodegradation at 5.7564 min−1 (efficiency 89 %), p-nitrophenol 0.00492 min−1 (efficiency 74 %), and chromium ions adsorption appeared at 0.13381 min−1 (efficiency 54 %). The study confirms the hybrid nanocomposite is a promising candidate as a novel membrane for clean water production.

Spectroscopic study of methylene blue photophysical properties in biological media

A spectroscopic study of the photophysical properties of methylene blue (MB) in aqueous solutions was carried out. Absorption and fluorescence spectra as well as fluorescence lifetime were recorded. The concentration dependence of the intensity and shape of the spectra allowed establishing the ranges of MB concentrations for in vitro and in vivo studies at which aggregation is not observed (up to 0.01 mM, which corresponds to 3.2 mg/kg). Studies of photodegradation in biological media showed that photobleaching of more than 80% in plasma and culture media is observed already at a dose of 5 J/cm2 , while in water at this concentration and dose photobleaching is not yet observed, and at a dose of 50 J/cm2 photobleaching of MB is about 30%. It was found that in media containing proteins and having an alkaline pH, photobleaching occurs significantly faster than in neutral aqueous media. The ionic strength of the solution has no effect on the photobleaching rate. Such photobleaching is caused by the photodegradation of MB rather than the transition to the leucoform.The efficiency of singlet oxygen generation and photodynamic activity were evaluated in vitro. In the investigated range of MB concentrations, the efficiency of singlet oxygen generation is rather low, because positively charged MB binds to negatively charged cell membranes, which leads to a change in the type of photodynamic reaction. The emergence of other reactive oxygen species (ROS), different from singlet oxygen, in cells has been demonstrated. The generation of ROS and the low quantum yield of singlet oxygen generation indicate the tendency of MB to provide the type I photosensitization mechanism (electron transfer with the formation of semi-reduced and semi-oxidized MB+ radicals) rather than to the type II mechanism (energy transfer to oxygen with the formation of singlet oxygen) in biological media and in vivo.

Using a Novel Heterojunction CoWO4/g-C3N4 as Visible Light Photocatalyst for Photodegradation of Organic Pollutant

Methylene Blue (MB) is a common dye that has various applications in different fields, including medicine, biology, and environmental science. While it can be beneficial in certain contexts, it can also have negative effects on the environment under certain circumstances. In this study, the photodegradation of MB under visible light irradiation using a novel heterojunction CoWO4/g-C3N4 catalyst was investigated. A series of CoWO4/g-C3N4 composites were synthesized and characterized using various techniques, including XRD, SEM, SEM-EDS, FT-IR, and UV–DRS. The results revealed that the 0.3CoWO4/g-C3N4 composite showed the highest efficiency (93%) in degrading MB during the 80-minute photodegradation process, aligning with the pseudo-first-order kinetics. The results provide clear evidence that the formation of CoWO4/g-C3N4 heterojunction greatly enhances the efficiency of photocatalysis by facilitating the swift separation of electron-hole pairs and boosting the redox capability. Additionally, the photodegradation efficiency remained above 90% even after four cycles, suggesting the stability of the catalyst.

Sonosynthesis of manganese ferrite nanoparticles on the cellulosic fabric and production of colored nanocomposite with magnetic and photocatalytic properties via statistically optimized method

Cellulosic fibers provide a favorable substrate for nucleation and growth of the nanoparticles. Manganese ferrite nanoparticles can serve as catalysts for various purposes. Here, sonosynthesis of manganese ferrite nanoparticles on cotton fabric was carried out through sonochemical processing by using iron chloride and manganese chloride salts at different temperatures and times in alkaline media. Also, the central composite design based on the response surface methodology was used to optimize the production conditions such as temperature and time. The formation of synthesized nanoparticles on cotton was evaluated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and elemental mapping tests. FESEM images confirmed the spherical manganese ferrite nanoparticles with an average size of 48 nm on cotton fabric. The photocatalytic activities, washing and lightfastness, and magnetic, mechanical, and colorimetric properties of the modified fabrics were investigated. The nanocomposites boosted methylene blue photodegradation under sunlight. In addition, the vibrating sample magnetometer (VSM) test indicated the paramagnetic nature of the manganese ferrite nanoparticles with a magnetic saturation of 1.32 emu/g. The treated fabrics with the proper magnetic properties are suitable for use in diverse applications such as supercapacitors.

Development and Upscaling of SiO2@TiO2 Core-Shell Nanoparticles for Methylene Blue Removal.

SiO2@TiO2 core-shell nanoparticles were successfully synthesized via a simple, reproducible, and low-cost method and tested for methylene blue adsorption and UV photodegradation, with a view to their application in wastewater treatment. The monodisperse SiO2 core was obtained by the classical Stöber method and then coated with a thin layer of TiO2, followed by calcination or hydrothermal treatments. The properties of SiO2@TiO2 core-shell NPs resulted from the synergy between the photocatalytic properties of TiO2 and the adsorptive properties of SiO2. The synthesized NPs were characterized using FT-IR spectroscopy, HR-TEM, FE-SEM, and EDS. Zeta potential, specific surface area, and porosity were also determined. The results show that the synthesized SiO2@TiO2 NPs that are hydrothermally treated have similar behaviors and properties regardless of the hydrothermal treatment type and synthesis scale and better performance compared to the SiO2@TiO2 calcined and TiO2 reference samples. The generation of reactive species was determined by EPR, and the photocatalytic activity was evaluated by the methylene blue (MB) removal in aqueous solution under UV light. Hydrothermally treated SiO2@TiO2 showed the highest adsorption capacity and photocatalytic removal of almost 100% of MB after 15 min in UV light, 55 and 89% higher compared to SiO2 and TiO2 reference samples, respectively, while the SiO2@TiO2 calcined sample showed 80%. It was also observed that the SiO2-containing samples showed a considerable adsorption capacity compared to the TiO2 reference sample, which improved the MB removal. These results demonstrate the efficient synergy effect between SiO2 and TiO2, which enhances both the adsorption and photocatalytic properties of the nanomaterial. A possible photocatalytic mechanism was also proposed. Also noteworthy is that the performance of the upscaled HT1 sample was similar to one of the lab-scale synthesized samples, demonstrating the potentiality of this synthesis methodology in producing candidate nanomaterials for the removal of contaminants from wastewater.

Constructing novel inorganic-organic α-Fe2O3/SNW-1 Z-scheme heterojunction for Methylene Blue photodegradation

A novel organic/inorganic heterostructured photocatalyst binary nanocomposite was typically prepared by the solvothermal method. The overwhelming superiority of this composite has been confirmed by spectroscopic and characterization methods, where the addition of α-Fe2O3 reduced the agglomeration of the Schiff-based covalent organic framework SNW-1 and significantly increased the specific surface area. The effects of operating parameters such as catalyst dosage, initial solution concentration, and pH on photocatalytic degradation of methylene blue (MB) dye were carefully investigated. Among them, a UV irradiation time of 80 min, a powder dose of 0.6 g/L, and pH=2 were the best choice. Under these favorable conditions, the α-Fe2O3/SNW-1 system exhibited excellent photocatalytic performance, and the degradation rate of MB reached more than 95%. In addition, the photocatalytic degradation efficiency of the pollutants acid orange 7 (AO7), rhodamine-B (RhB), and acid red (ArB) comfortably reached 92%, 92%, and 91%, respectively. After five cycles of testing, the prepared photocatalyst showed good stability and reusability. Through energy band calculation, free radical quenching experiment, and electron paramagnetic resonance (ESR) study, it was discovered that the main active substances were ·O2- and ·OH, and the photogenerated holes and electrons also participated in the photocatalytic reaction. The Z-scheme charge transfer mechanism of α-Fe2O3/SNW-1 was proposed. Photoelectric chemical tests further demonstrated the extraordinary photocatalytic activity, low internal resistance, and high carrier separation capability of the binary nanocomposites. This study presents the potential application of high-performance photocatalysts for the removal of organic dyes in water purification.

The design and preparation of Mg and Zn co-doped carbon nitride with enhancing photocatalytic degradation efficiency for methylene blue

Carbon nitride (g-C3N4) is a potential material that can be used for the treatment of the wastewater contains organic dyes. However, the photocatalytic efficiency of g-C3N4 is limited by the wide band gap and fast recombination of photon-generated carriers. In this work, the co-doped with Mg and Zn of MgZn0.07-g-C3N4 was designed and prepared to enhance the photocatalytic efficiency. The co-doped Mg and Zn shorted the band gap of g-C3N4 from 2.74 eV to 2.50 eV. Interestingly, according to the DFT calculation, a Zn-bridge is formed between the interlayers of g-C3N4. The Zn-bridge reduces the electron localization and prolongs the existence time of photon-generated carriers. The as-prepared MgZn0.07-g-C3N4 was applied for the photodegradation of methylene blue. The degradation ratios and photodynamic parameter of MgZn0.07-g-C3N4 are higher than that of g-C3N4 and Mg-g-C3N4 (29.51 × 10−3 min vs 8.00 × 10−3 min).