rGO Heterostructure Research Articles

Facile synthesis and first principles calculations of Li-MoS2/rGO nanocomposite for high-performance supercapacitor applications

Two-dimensional (2D) nanostructured materials such as graphene oxide nanosheets and molybdenum disulfide (MoS2) are potential candidates for electrochemical energy storage applications. The layered structure of MoS2 makes it a promising active electrode material for supercapacitors. Lithium (Li) interacted with MoS2/reduced graphene oxide (Li-MoS2/rGO) nanocomposite has been synthesized in two steps using a sonochemical dispersion method, and a one-pot hydrothermal method resulting in few-layered MoS2/rGO nanosheets of 2D heterointerfaces. The Li-MoS2/rGO nanocomposite exhibits a high specific capacitance of 173.3 F g−1 at a current density of 1 A g−1. Furthermore, an asymmetric supercapacitor device fabricated with Li-MoS2/rGO achieves a good energy density of 10.6 Wh kg−1 at a power density of 686.3 W kg−1 and outstanding cycling stability with 81.2 % capacity retention over 10,000 cycles. The dispersion of 2D-MoS2 in water is due to the strong electrostatic interface. The structural and electronic properties are theoretically calculated for pristine and Li-interacted MoS2/rGO heterostructure using density functional theory. A comparison of the density of states plots of the two heterostructures and the difference charge density plot of Li-MoS2/rGO heterostructure clearly brings out the importance of the presence of Li. A value of 64 μF cm−2 for the quantum capacitance for pristine MoS2/graphene heterostructure increases to a value 99 μF cm−2 corroborating the experimental observations and we assign this change to the transfer of charge from the Li atom to the outer S atoms in the MoS2/graphene heterostructure. This comprehensive approach, combining experimental synthesis with computational modelling, significantly advances the development and optimization of high-performance supercapacitor materials in the energy storage field. The Li-MoS2/rGO nanocomposite has excellent electrochemical specific capacitance and long-term cyclic stability and has been effectively used for supercapacitor applications with high electrochemical performance.

Enhanced dopamine detection using Ti3C2Tx/rGO/Pt ternary composite synthesized via microwave-assisted hydrothermal method

A novel electrochemical sensing platform for dopamine (DA) detection was developed by fabricating the ternary composite of Ti3C2Tx MXene (M) and reduced graphene oxide (rGO) with platinum nanoparticles (Pt NPs) through microwave-assisted hydrothermal heating. The exceptional electrical conductivity and rich surface chemistry of MXene provide abundant active catalytic sites for electrochemical reactions, while the large surface area of rGO facilitates ion and electron pathways. The integration of rGO in the MXene sheet, forming MXene-rGO (M_rGO) heterostructure composite, imparts long-term stability to the 2D heterostructure while providing additional electron pathways and significantly enhancing conductivity. Pt NPs synergistically increased the electrocatalytic activity of the electrochemical sensor's performance. Ternary nanocomposites were fabricated with different weight percentages (wt.%) of Pt NPs, ranging from 5 to 20. Characterizations of the samples (rGO, M, M_rGO, and 5–20 wt% Pt@M_rGO) were conducted through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy (RAMAN), and X-ray spectroscopy (XPS). Electrochemical evaluations of the samples were investigated in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analyses. The analysis revealed that the ternary composite with 5 wt% of Pt NPs (5% Pt@M_rGO) exhibited a uniform well-distribution of Pt NPs and the highest oxidation peak for DA oxidation in CV studies. The presence of metal nanoparticles, aided by the synergistic effects between the MXene and rGO, resulted in an excellent DA sensor with a 0.147 μM detection limit from 1 to 14 μM linearity range. The sensor demonstrated outstanding selectivity, reproducibility (RSD values of 8.10%), repeatability (RSD value of 2.46%) and, excellent stability over 14 days. In human urine samples, the sensor exhibited excellent DA recovery (88.62–110.65%). This study significantly advances the development of electrochemical sensors for DA detection by introducing a rapid, facile and, efficient method for fabricating ternary composites. The fabricated sensor exhibited high sensitivity, excellent selectivity, and robust electrochemical performance, offering valuable insights into human and behavioral health advancements.

Graphene heterostructure fiber with enhanced physicochemical properties for flexible solid-state supercapacitors

The graphene/pseudocapacitive composite electrode materials used for energy storage usually benefit from the advantages of each component, however, they also face significant challenges in terms of structural integrity and rate performance due to the weak interactions and limited interface area between different phases. To tackle these issues, we propose a facile strategy that integrates 2D/2D van der Waals forces and hydrogen bonds to effectively and closely bind each component together. We illustrate this concept by designing and constructing a heterojunction fiber that immobilizes protonated g-C3N4 onto GO nanosheets through electrostatic self-assembly. The resulting g-C3N4/RGO heterostructure fiber exhibits enhanced electrical conductivity and improved mechanical properties. When utilized as a supercapacitor electrode, it demonstrates high specific capacitances of 70.6 F cm−3 at a current density (Id) value of 0.1 A cm−3, in addition to exceptional cyclic stability (Retaining 99.4 % after 15000 cycles), rate capability (Retaining 55.8 % at Id = 2 A cm−3), and enduring mechanical flexibility. We anticipate that this study will inspire the fabrication of heterostructure fibers for durable and high-rate energy storage devices.

Oxygen doping and interface engineering in O-MoS2&rGO heterostructure for efficient piezocatalytic dye degradation

Oxygen doping and interface engineering in O-MoS2&rGO heterostructure for efficient piezocatalytic dye degradation

Interface engineering to construct heterostructured SnS2/Sb2S3 on rGO through a targeted-complexation deposition strategy for high-performance lithium-ion capacitors

Accurate synthesis of electrode materials with homogeneous heterostructure is an important approach to eliminate the energy storage dynamics discrepancy between the anode and cathode of lithium-ion capacitors (LICs). However, the complex synergistic effects between two electrodes is yet to materialize due to the lack of effective approach. Herein, a targeted-complexation deposition strategy is proposed to prepare uniform SnS2/Sb2S3 heterostructure attached to reduced graphene oxide (rGO) (SnS2/Sb2S3@rGO) with the aid of L-cysteine. The strong complexation between L-cysteine and metal ions effectively suppresses the hydrolysis reaction of Sb3+ ion and guides the uniform deposition of SnS2/Sb2S3 heterostructures on rGO. Due to the charge redistribution and mutual-support effect, the lithium storage properties of SnS2/Sb2S3@rGO can be integrated and greatly enhanced. Furthermore, a three-dimensional conductive network consisting of polyaniline and rGO heterostructure is synthesized by a self-assembly strategy, which is able to deliver a superior capacity of 178.6 mA h g−1 as well as outstanding rate property as a cathode. The LICs assembled with heterogeneous cathode and anode materials demonstrates an exceptional energy density (reaching 298 W h kg−1), impressive power density (58.5 kW kg−1) and remarkable capacity maintenance (78 %) even over 6000 cycles, providing a valuable guide for producing the high-performance LICs.

Heterostructure assembled by organic-molecule intercalated MoS2 and reduced graphene oxide for enhanced interface energy and supercapacitor performance

Organic molecule intercalation and heterostructure construction can optimize the capacitive storage of MoS2. To begin with, we choose MoO3 as the molybdenum source and polypyrrole (PPy) as the intercalation agent to synthesize the enlarged interlayer spacing MoS2 (MoS2-PPy). On this basis, MoS2-PPy@reduced graphene oxide (rGO) heterostructures are eventually fabricated. The electrochemical merits of rGO and MoS2-PPy can be combined through synergistic effects among the heterostructure. What's more, to examine the kinetics storage mechanisms of MoS2 samples, density functional theory (DFT) calculations have been done. It turns out the introduction of rGO enhanced the polarity of MoS2, which lead to stronger interface energy and additional capacitance. Additionally, for the involvement of rGO, the conductivity has been effectually elevated. Moreover, an AC//MoS2-PPy@rGO asymmetric flexible device is assembled, and it have an excellent energy density of 134.4 µWh cm−2 at a power density of 800 µW cm−2. This work paves the way for constructing organic-molecular intercalated-MoS2 based heterostructures in capacitive energy storage.

Novel CuBi2O4-BiOCl/rGO heterostructure nanocomposite as high-performance visible light photocatalyst for the disintegration of persistent antimicrobials in aquatic environment

The article highlights the fabrication of a novel CuBi2O4-BiOCl/rGO heterojunction nanocomposite as a renewable visible light photocatalyst for the quick disintegration of a persistent fluoroquinolone-based antimicrobial drug, i.e., enrofloxacin (ENF) in aquatics. CuBi2O4-BiOCl (CBO-BOC) nanocomposites (NCs) of varying BOC stoichiometric ratios were synthesized, of which CBO-(30%) BOC NC (CB-30) revealed top photocatalytic traits, which was analogously dispersed onto reduced graphene oxide (rGO) nanosheets, to serve as the visible light photon responsive materials. The electron microscopic and spectroscopic techniques were deployed to understand the CB-30/rGO heterostructure's surface topography and structural morphology. The FE-SEM, HR-TEM and XPS analysis confirmed the dispersion of CBO nanospheres onto the BOC nanoflakes and further confirmed the successful imbuement of CB-30 NCs onto the rGO nanosheets. The CB-30/rGO photocatalyst revealed excellent porosity and surface area for the fast dissipation of pharmaceutical pollutants. The impact of various operating parameters, such as solution pH, drug concentration, CBO-BOC stoichiometry, CB-30/rGO dosage, photosensitizers/electron acceptors, light intensity and matrix tolerance limits, were augmented to enhance the photocatalytic efficiency of the proposed new-age photocatalyst. Under optimized conditions, complete drug mineralization was achieved in ≤0.33 h for complete mineralization of 30 ppm of ENF, using 0.075 g of photocatalyst. The time-dependent profiling of photoproducts/intermediates derived from the photocatalytic degradation of ENF was monitored by HR-MS analysis. The acute and chronic toxicity effects of ENF and its organic intermediate were predicted using the ECOSAR model for selected aquatic life forms. The photocatalyst exhibited reusability up to seven cycles, with excellent thermal/chemical stability, for pollutant decontamination from industrial effluents and environmental samples.

Integrating multiple regulatory strategies: phase, morphology and interface engineering to construct a hierarchical Ni2P–MoS2/rGO heterostructure catalyst for efficient oxygen reduction reaction

Two-dimensional (2D) molybdenum disulfide (MoS2) with a large surface area and unique electronic properties has emerged as a promising noble metal-free catalyst for electrochemical energy storage/conversion applications.

Construction of CsPbBr3/carboxyl-modified rGO heterostructures for efficient photocatalytic reduction of CO2 to methanol

Construction of monodispersed CsPbBr3 NCs and carboxyl-modified rGO composites led to the production of CO and CH3OH with an Relectron of 359 μmol g−1 h−1 by photocatalytic CO2 reduction.

3D hierarchical Ti3C2Tx@NiCo2S4–RGO heterostructure hydrogels as free-standing electrodes for high-performance supercapacitors

A high-energy supercapacitor device based on 3D hierarchical free-standing Ti3C2Tx@NiCo2S4–RGO heterostructure hydrogel electrodes is assembled.

Superior cyclic stability and electrochemical performance of La supported Bi2S3@g-C3N4//rGO heterostructure composite for asymmetric supercapacitor devices

To improve the cyclic stability of Bi2S3 transition metal dichalcogenides (TMD), rare-earth lanthanum (La) supported Bi2S3@g-C3N4 was synthesized via a simple solvothermal method. The physicochemical properties of the electrode material were investigated by using various characterization techniques such as XRD, FTIR, FT Raman, HRSEM, XPS, BET, HRTEM and SAED. From HRTEM image that La doped Bi2S3@g-C3N4 heterostructure composite revealed in which the 2D layered g-C3N4 nanosheets decorated 1D nanorods of La doped Bi2S3. 10 mol% La doped Bi2S3@g-C3N4 heterostructure composite attained a higher specific capacity of 1880 C/g at 1 A/g by increasing active sites for diffusion ions due to enhanced surface area (131.4 m2/g). The aqueous asymmetric supercapacitor device was assembled using the La doped Bi2S3@g-C3N4 positive electrode and the rGO negative electrode with 1 M KOH electrolyte. This supercapacitor displayed a specific capacitance of 61 F/g at 2 mA/g, a maximum power density of 666 W/kg, an energy density of 1.7 W h/kg, and a capacitance preservation of 64% even after 10,000 cycles. 10 mol% La doped Bi2S3@g-C3N4 heterostructure composite persist excellent kinetic and electrochemical reversibility, intrinsic electrical conductivity, and remarkable cyclic stability.

Effect of adsorbate geometry and hydrogen bonding on the enhanced adsorption of VOCs by an interfacial Fe3O4–rGO heterostructure

Volatile organic compounds (VOCs) produced from a wide range of industrial and household chemicals are toxic to human health. Hence, effective VOC removal strategies such as adsorption are essential. Developing a carbon-based adsorbent for the selective adsorption of VOCs without affecting its inherent adsorption capacity is challenging. In this study, we prepared three Fe3O4-doped reduced graphene oxide (Fe-rGO) materials via a liquid-phase reduction technique under acidic, neutral, and basic coagulation conditions. The Fe-rGO adsorbents exhibited a hydrolysis-induced GO network with a wrinkled layer morphology. Acidic conditions yielded an rGO surface with a large number of O-functional groups (epoxy and carboxylic groups), which act as anchoring sites for the growth of Fe3O4 nanoparticles. The synergistic effect of Fe3O4 domains and O active sites led to the effective and selective adsorption of amphiphilic VOCs including C4-C7 alkanes, ketones, and aromatic compounds (10.8–63.2 mg g−1). Experimental analyses and density functional theory calculations revealed three crucial factors that determine the improved amphiphilic VOC adsorption of the Fe-rGO materials: geometry of the adsorbate, hydrogen bonding at the rGO surface, and Fe3O4 nanoparticles controlling the charge density. Our facile and effective rGO surface manipulation strategy involving the fabrication of a metal oxide–carbon heterostructure provides a selective adsorption platform for amphiphilic VOCs.

Cation-Driven Assembly of Bilayered Vanadium Oxide and Graphene Oxide Nanoflakes to Form Two-Dimensional Heterostructure Electrodes for Li-Ion Batteries.

Lithium preintercalated bilayered vanadium oxide (LVO or δ-LixV2O5·nH2O) and graphene oxide (GO) nanoflakes were assembled using a concentrated lithium chloride solution and annealed under vacuum at 200 °C to form two-dimensional (2D) δ-LixV2O5·nH2O and reduced GO (rGO) heterostructures. We found that the Li+ ions from LiCl enhanced the oxide/carbon heterointerface formation and served as stabilizing ions to improve structural and electrochemical stability. The graphitic content of the heterostructure could be easily controlled by changing the initial GO concentration prior to assembly. We found that increasing the GO content in our heterostructure composition helped inhibit the electrochemical degradation of LVO during cycling and improved the rate capability of the heterostructure. A combination of scanning electron microscopy and X-ray diffraction was used to help confirm that a 2D heterointerface formed between LVO and GO, and the final phase composition was determined using energy-dispersive X-ray spectroscopy and thermogravimetric analysis. Scanning transmission electron microscopy and electron energy-loss spectroscopy were additionally used to examine the heterostructures at high resolution, mapping the orientations of rGO and LVO layers and locally imaging their interlayer spacings. Further, electrochemical cycling of the cation-assembled LVO/rGO heterostructures in Li-ion cells with a non-aqueous electrolyte revealed that increasing the rGO content led to improved cycling stability and rate performance, despite slightly decreased charge storage capacity. The heterostructures with 0, 10, 20, and 35 wt % rGO exhibited capacities of 237, 216, 174, and 150 mAh g-1, respectively. Moreover, the LVO/rGO-35 wt % and LVO/rGO-20 wt % heterostructures retained 75% (110 mAh g-1) and 67% (120 mAh g-1) of their initial capacities after increasing the specific current from 20 to 200 mA g-1, while the LVO/rGO-10 wt % sample retained only 48% (107 mAh g-1) of its initial capacity under the same cycling conditions. In addition, the cation-assembled LVO/rGO electrodes exhibited enhanced electrochemical stability compared to electrodes prepared through physical mixing of LVO and GO nanoflakes in the same ratios as the heterostructure electrodes, further revealing the stabilizing effect of a 2D heterointerface. The cation-driven assembly approach, explored in this work using Li+ cations, was found to induce and stabilize the formation of stacked 2D layers of rGO and exfoliated LVO. The reported assembly methodology can be applied for a variety of systems utilizing 2D materials with complementary properties for applications as electrodes in energy storage devices.

Light-Dependent A.C. Transport Properties of Zinc Oxide (ZnO)/Reduced Graphene Oxide (rGO) Heterostructure Device: A Signature of Electrical Memory

Light-Dependent A.C. Transport Properties of Zinc Oxide (ZnO)/Reduced Graphene Oxide (rGO) Heterostructure Device: A Signature of Electrical Memory

Multifunctional Nanocrystalline-Assembled Porous Hierarchical Material and Device for Integrating Microwave Absorption, Electromagnetic Interference Shielding, and Energy Storage.

Multifunctional applications including efficient microwave absorption and electromagnetic interference (EMI) shielding as well as excellent Li-ion storage are rarely achieved in a single material. Herein, a multifunctional nanocrystalline-assembled porous hierarchical NiO@NiFe2 O4 /reduced graphene oxide (rGO) heterostructure integrating microwave absorption, EMI shielding, and Li-ion storage functions is fabricated and tailored to develop high-performance energy conversion and storage devices. Owing to its structural and compositional advantages, the optimized NiO@NiFe2 O4 /15rGO achieves a minimum reflection loss of -55dB with a matching thickness of 2.3mm, and the effective absorption bandwidth is up to 6.4GHz. The EMI shielding effectiveness reaches 8.69dB. NiO@NiFe2 O4 /15rGO exhibits a high initial discharge specific capacity of 1813.92 mAh g-1 , which reaches 1218.6 mAh g-1 after 289 cycles and remains at 784.32 mAh g-1 after 500 cycles at 0.1 A g-1 . In addition, NiO@NiFe2 O4 /15rGO demonstrates a long cycling stability at high current densities. This study provides an insight into the design of advanced multifunctional materials and devices and provides an innovative method of solving current environmental and energy problems.

Confined growth of NiCo2S4 on 2D/2D porous carbon self-repairing g-C3N4/rGO heterostructure for enhanced performance of asymmetric supercapacitors

In this work, porous carbon self-repairing g-C3N4 (pCCN) nanosheets were synthesised using a solvothermal technique followed by calcination and acid treatment. A facile hydrothermal process is employed for the confined growth of NiCo2S4 on porous carbon self-repairing g-C3N4/rGO heterostructure (pCRNCS) as hybrid material for supercapacitor electrodes. The improved electronic conductivity and activity of carbon self-repairing g-C3N4 (CCN) than g-C3N4 owing to the creation of extended delocalized π-electrons by the substitutional or interstitial C atoms in the structure and because of acid treatment, the larger planes of CCN are broken down into smaller segments, increasing the edge nitrogen and oxygen functional groups. The introduction of porous CCN led to the strong electrostatic interaction with GO and CCN which aided in the suppression of agglomeration of graphene sheets. The as-synthesised pCRNCS electrode showed remarkably high specific capacitance (1938 F/g at current density of 2 A/g). The excellent electrochemical activity is due to the 2D/2D heterostructure assembly of high surface area rGO and extended highly reactive region and defects in pCCN which facilitated the nucleation and confined growth of NiCo2S4 in the framework. The constructed pCRNCS//AC ASC exhibited remarkable electrochemical properties, including a specific capacitance of 211 F/g at 1 A/g, an exceptional capacitance retention of 93.6% after 6000 cycles, and the maximum energy density of 66 Wh/kg at a power density of 751 W/kg. The excellent capacitive behaviour of porous carbon self-repairing g-C3N4/rGO@NiCo2S4 assure the development of high-performance energy storage device.

Few-layered Ti3C2TXcoupled with Fe3O4nanoparticles assembled in a reduced graphene oxide hydrogel as advanced electrodes for high-energy supercapacitors

A high-performance symmetric supercapacitor device based on free-standing 3D porous Fe3O4@Ti3C2TX–rGO heterostructure hydrogel electrodes is built.

Atypical performance of CoO-accelerated interface tweaking in hierarchical cobalt phosphide/oxide@P-doped rGO heterostructures for hybrid supercapacitors

Designing two-dimensional (2D) heterostructures based on suitable energy materials is a promising strategy to achieve high-performance supercapacitors with hybridized transition metal and carbonaceous-based electrodes. The influence of each component and its content on the capacitor performance necessitates deeper insights. In this study, a 2D/2D heterostructure made of hierarchical pseudocapacitive cobalt phosphide/oxide and P-doped reduced graphene oxide (PrGO) nanosheets (CoP/CoO@PrGO) was fabricated using porous zeolitic-imidazolate framework precursor. The decoration of 2D leaf-like CoP/CoO hybrid onto PrGO could create a unique interface with a large number of active sites, CoO-driven creation of pseudocapacitive surface POx species, and high P content (∼3 at.%) in PrGO, thus promoting the Faradaic reaction, electrical conductivity, and overall charge storage. This framework yields a high specific capacitance of 405 F g−1 at 5 A g−1 and excellent cycling stability (over 100 % after 10,000 cycles), superior to those of pristine CoP@PrGO (300 F g−1 at 5 A g−1). Furthermore, the fabricated asymmetric supercapacitor delivers reasonable energy density of 4.2 Wh kg−1 at a power density of 785 W kg−1 and cycling stability of ∼100 % after 10,000 cycles. Therefore, CoP/CoO@PrGO with its unique interfacial properties can promote the development of heterostructure electrode for high-performance supercapacitors.

Two-dimensional layered molybdenum disulfide (MoS2)-reduced graphene oxide (rGO) heterostructures modified with Fe3O4 for electrochemical sensing of epinephrine

An epinephrine (also known as adrenaline) molecule plays an important role in neurotransmission. Human body is very sensitive to the change in its concentration and its alteration results, many neurological disorders including Parkinson's and Alzheimer's disease. Hence, the sensitivity and selectivity detection of epinephrine is a significant area of study for the diagnosis of diseases due to their abnormal level in body. The sensing of epinephrine has been carried out at biological pH. In the present work, reduced graphene oxide (rGO)-molybdenum disulfide (MoS2) decorated Fe3O4 (rGO-MoS2@Fe3O4) nanocomposite was synthesized using microwave-assisted method for the electrochemical detection of epinephrine. The as-synthesized rGO-MoS2@Fe3O4 nanocomposite material was characterized to study the morphological and structural analysis by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and Raman spectroscopy techniques. In comparison to the bare glassy carbon electrode, rGO-MoS2@Fe3O4 nanocomposite exhibited superior electrocatalytic activity by decreasing the peak potential from 0.3 to 0.2 V and increasing the peak current from 26 μA to 42 μA (61% higher). Compared with reported literature, the rGO-MoS2@Fe3O4 nanocomposite was found to show a lower limit of detection of 1.37 μM and good sensitivity of 2.87 μAμM−1cm−2. Thus, from these results, it is concluded that the as-synthesized rGO-MoS2@Fe3O4 nanocomposite shows improved electrocatalytic properties.

Synergetic Nanoarchitectonics of Defects and Cocatalysts in Oxygen-Vacancy-Rich BiVO4/reduced graphene oxide Mott-Schottky Heterostructures for Photocatalytic Water Oxidation.

Water oxidation process is a pivotal step of photosynthesis and stimulates the progress of high-performance catalysts for renewable fuel production. Despite the performance benefit of cocatalysts, defect engineering holds promise to settle inherent limitations of semiconductors aiming at sluggish water oxidation. Here, we modify the in situ growth pathway of monoclinic BiVO4 (m-BiVO4) on reduced graphene oxide (rGO), constructing abundant surface oxygen vacancies (OV)-incorporated m-BiVO4/rGO heterostructure toward water oxidation reaction under visible light. Owing to the OV in the m-BiVO4 component, a vacancy-related defect level allows more electrons to be photoexcited by low-energy photons to cause the electron transition, boosting photoabsorption as well as photoexcitation. Besides, the OV can reinforce surface adsorption and reduce the dissociation energy of water molecules. Particularly because of the synergy of OV and cocatalyst rGO, the OV functions as electron-trapped sites to facilitate the carrier separation; the rGO not only receives electrons from m-BiVO4 promoted by internal electric field over Mott-Schottky heterostructures but also spurs further electron diffusion along a highly conductive carbon network. These merits enable the OV-incorporated m-BiVO4/rGO heterostructure with an over 209% growth in O2 yield relative to the counterpart. The increased performance is also validated by the significant rise of •OH radicals and •O2- radicals. The current work paves a novel avenue for the integration of defect engineering and cocatalyst coupling in artificial photosynthesis.