Rationally designed ternary CdSe/WS2/g-C3N4 hybrid photocatalysts with significantly enhanced hydrogen evolution activity and mechanism insight

Excellent light harvest, efficient charge separation and sufficiently exposed surface active sites are crucial for a given photocatalyst to obtain excellent photocatalytic performances. The construction of two-dimensional/two-dimensional (2D/2D) or zero-dimensional/2D (0D/2D) binary heterojunctions is one of the effective ways to address these crucial issues. Herein, a ternary CdSe/WS₂/g-C₃N₄ composite photocatalyst through decorating WS₂/g-C₃N₄ 2D/2D nanosheets (NSs) with CdSe quantum dots (QDs) was developed to further increase the light harvest and accelerate the separation and migration of photogenerated electron-hole pairs and thus enhance the solar to hydrogen conversion efficiency. As expected, a remarkably enhanced photocatalytic hydrogen evolution rate of 1.29 mmol g⁻¹ h⁻¹ was obtained for such a specially designed CdSe/WS₂/g-C₃N₄ composite photocatalyst, which was about 3.0, 1.7 and 1.3 times greater than those of the pristine g-C₃N₄ NSs (0.43 mmol g⁻¹ h⁻¹), WS₂/g-C₃N₄ 2D/2D NSs (0.74 mmol g⁻¹ h⁻¹) and CdSe/g-C₃N₄ 0D/2D composites (0.96 mmol g⁻¹ h⁻¹), respectively. The superior photocatalytic performance of the prepared ternary CdSe/WS₂/g-C₃N₄ composite could be mainly attributed to the effective charge separation and migration as well as the suppressed photogenerated charge recombination induced by the constructed type-II/type-II heterojunction at the interfaces between g-C₃N₄ NSs, CdSe QDs and WS₂ NSs. Thus, the developed 0D/2D/2D ternary type-II/type-II heterojunction in this work opens up a new insight in designing novel heterogeneous photocatalysts for highly efficient photocatalytic hydrogen evolution.     

Graphite carbon nitride loaded nitrogen-doped carbon and cobalt nanoparticles ternary photocatalyst for enhanced solar-driven hydrogen evolution

In this paper, we designed a composite photocatalytic system in which cobalt nanoparticles (Co NPs) are attached to nitrogen-doped carbon (N-d-C) and co-bonded to the surface of the noted photocatalyst graphite carbon nitride (g-C₃N₄), showing an excellent photocatalytic hydrogen production. The bulk g-C₃N₄ was formed in the first thermal treatment in air using melamine as a precursor. Subsequently, the secondary calcination under N₂ led to the synchronous fabrication of N-d-C/Co NPs and their combination with g-C₃N₄ to form a novel ternary photocatalyst (g-C₃N₄/N-d-C/Co NPs). Co NPs exposed on the surface of the nanomaterials endowed much more reaction sites than g-C₃N₄ for photocatalytic hydrogen production. Meanwhile, the embedded N-d-C provided an additional transfer approach for photocarriers. The as-prepared composite nanomaterials own a relatively high specific surface area of 97.45 m² g^?1 with an average pore size of 3.83 nm. As a result, compared with pristine g-C₃N₄ (～25.35 μmol g^?1 h^?1), the photocatalytic performance was increased by over 10 times (～270.05 μmol g^?1 h^?1). Our work gives a novel approach for highly active g–C₃N₄–based photocatalysts in the field of photocatalysis.     

MnO2 nanowires anchored on mesoporous graphitic carbon nitride (MnO2@mpg-C3N4) as a highly efficient electrocatalyst for the oxygen evolution reaction

In the present study, we report the rational design and fabrication of a novel nanocomposite, namely one-dimensional (1D) MnO₂ nanowires grew up in situ within the 2D mesoporous carbon nitride (MnO₂@mpg-C₃N₄), as a highly efficient electrocatalyst for OER. The structural, morphological and thermal properties of as-prepared MnO₂@mpg-C₃N₄ electrocatalyst were characterized by TEM, SEM, XRD, XPS, Raman, ICP-MS, and TGA. The results clearly revealed the formation of 3D-hierarchical heterostructures consisting of 1D MnO₂ nanowires anchored on mpg-C₃N₄. Next, the electrocatalytic performance of MnO₂@mpg-C₃N₄ nanocomposite was tested in OER wherein it exhibited substantially enhanced activity than pristine 1D MnO₂ nanowires. In particular, the turnover frequency (TOF) of MnO₂@mpg-C₃N₄ (0.84 s⁻¹@480 mV) was found almost three times higher than that of 1D MnO₂ nanowires (0.32 s⁻¹@480 mV). Moreover, the overpotential and Tafel slope values were successfully lowered down by using MnO₂@mpg-C₃N₄ nanocomposite compared to those of 1D MnO₂ nanowires. It was experimentally demonstrated that the superior OER performance of the MnO₂@mpg-C₃N₄ is attributed to the effective stabilization of Mn³⁺ species (Mn₂O₃) in the electrocatalyst via the help of nitrogen functional groups of mpg-C₃N₄ and the formation of 3D heterostructure that offers the following three major contributions; i) enhanced aerophobicity due to orientation modifications of growing 1D MnO₂ nanowires, ii) open structure facilitating the rapid detachment of gas bubbles from the electrode surface, iii) a large number of transport channels for the penetration of electrolyte, ions and electrons.     

Interconnected Na2Ti3O7 nanotube/g-C3N4/graphene network as high performance anode materials for sodium storage

The high-performance anode electrode material has been the major challenge of sodium ion batteries (SIBs). In this paper, we report a facile strategy to fabricate three-dimensional (3D) network structures where Na₂Ti₃O₇ nanotube species are anchored to the composites composed of graphite phase carbon nitride (g-C₃N₄) and ultrafine graphene, and demonstrates the excellent electrochemical performance as a sodium storage material. The good integration of g-C₃N₄ and graphene provides more active sites for Na⁺ insertion/extraction and accommodates the volume expansion of Na₂Ti₃O₇. The Na₂Ti₃O₇ nanotube into these carbon matrix can effectively shorten the transport paths of Na⁺. Therefore, the Na₂Ti₃O₇NT/g-C₃N₄/RGO electrode exhibits a superior cycling efficiency and rate capability. When used as the anode material of sodium half-cell, the reversible capacity of the synthesized Na₂Ti₃O₇NT/g-C₃N₄/RGO composite is as high as 210.8 mAh g⁻¹ after 300 cycles at 0.1 A g⁻¹ and good rate capability (104.7 mAh g⁻¹ at 2 A g⁻¹). After the 50 cycle, the corresponding coulomb efficiency remained basically stable and is up to 98%. In addition, the half-cell provides high energy density of 364 Wh kg⁻¹ at power density of 0.048 W kg⁻¹.     

Functionalized 2D materials F–MoS2 and F-g-C3N4 with TiO2 as Composite Electrocatalysts for Electrochemical Hydrogen Evolution

Electrochemical hydrogen evolution is an important research field to produce renewable energy. Nanostructured two dimensional (2D) materials such as g-C₃N₄ and MoS₂ are potential electrocatalysts for hydrogen evolution reaction (HER). The incorporation of semiconducting material into 2D material enhances the hydrogen evolution. Here in, we have developed composite of acid functionalized MoS₂ and g-C₃N₄ with TiO₂ (F–MoS₂/TiO₂, F-g-C₃N₄/TiO₂). The F–MoS₂/TiO₂ composite exhibited excellent electrochemical HER activity with an overpotential of 103 mV Vs RHE at 20 mA/cm² compared to pristine F–MoS₂ of 232 mV, TiO₂ of 455 mV Vs RHE. In addition F-g-C₃N₄/TiO₂ showed high overpotential of 322 mV at 5 mA/cm² than pristine F-g-C₃N₄ and TiO₂ of 433 mV and 448 mV Vs RHE at 2.7 mA/cm² respectively.     

Direct Z-scheme CoS/g-C3N4 heterojunction with NiS co-catalyst for efficient photocatalytic hydrogen generation

Facilitating the separation of photoexcited electron-hole pairs and enhancing the migration of photogenerated carriers are essential in photocatalytic reaction. CoS/g-C₃N₄/NiS ternary photocatalyst was prepared by hydrothermal and physical stirring methods. The optimized ternary composite achieved a hydrogen yield of 1.93 mmol g^?1 h^?1, 12.8 times that of bare g-C₃N₄, with an AQE of 16.4% at 420 nm. The enhanced photocatalytic activity of CoS/g-C₃N₄/NiS was mainly ascribed to the synergistic interaction between the Z-scheme heterojunction constructed by CoS and g-C₃N₄ and the NiS co-catalyst featuring a large amount of hydrogen precipitation sites, which realized the efficient separation and migration of photogenerated carriers. In addition, the CoS/g-C₃N₄/NiS heterojunction-co-catalyst system exhibited excellent photocatalytic stability and recyclability.     

TiO2 nanorods decorated on RGO sheet for an excellent energy storage performance

Herein, we report nanocomposite of titanium dioxide (TiO₂) nanorods decorated reduced graphene oxide (TiO₂/RGO) nanocomposite prepared using the simple, one-pot hydrothermal route for electrode material in supercapacitor applications. A systematic comparison study was carried out for the TiO₂ nanorods coated on graphite foil in presence of alkaline media 3 M KOH, NaCl, and Na₂SO₄ using the three-electrode method. The TiO₂/RGO composite shows an excellent specific capacitance (C_sp) of 330 Fg^-1 at the discharge current density 0.5 Ag^-1 in presence of 3 M KOH electrolyte solution. The obtained highest specific capacitance values in order by various electrolytes are observed as KOH > NaCl > Na₂SO₄. The long-term cycle stability of charge and discharge cycle at current density 0.5 Ag^-1 over 1000 cycles and only 8% decay in the specific capacitance of TiO₂/RGO nanocomposite was observed in 3 M KOH electrolyte. The improved electrochemical performance TiO₂/RGOcomposite in presence of KOH electrolyte is shown to be the most suitable electrode for the supercapacitors.     

In- situ solid-phase fabrication of Ag/AgX (X=Cl,Br, I)/g-C3N4 composites for enhanced visible-light hydrogen evolution

In this work, a series of Ag/AgX (X = Cl, Br, I)/g-C₃N₄ (Ag/AgX/CN) composites were successfully fabricated by an in-situ solid phase method. The morphology and structure, photoluminescence and photoelectrochemical properties of composites were investigated in detail. The as-prepared Ag/AgX/CN composites were used as H₂ evolution photocatalysts under visible-light irradiation with a sacrificial agent. The experimental results revealed that Ag/AgI/CN-4 composite possesses highest-H₂ evolution rate (up to 59.22 μmol g⁻¹ h⁻¹) which are approximately 31 times higher than that of pure g-C₃N₄ (1.94 μmol g⁻¹ h⁻¹). In addition, Ag/AgCl/CN-4 and Ag/AgBr/CN-4 composites also present high photocatalytic activities yielding, 26.39 and 18.05 μmol_H2 g⁻¹ h⁻¹_, respectively. The enhanced photocatalytic activities of Ag/AgI/CN-4 composite might be attributed to the synergistic effect between Ag/AgI nanoparticles and g-C₃N₄ and the localized surface plasmon resonance effect of metallic Ag. Moreover, Ag/AgI/CN-4 composite showed excellent recyclability and stability after five cycling photocatalytic tests (about 25 h). Furthermore, the possible photocatalytic mechanism of Ag/AgI/CN composites is proposed.     

Compound SnS2 sensitizer in the S-scheme of Ag2Mo2O7/CoMoO4 heterojunction to improve the hydrogen evolution of semiconductor powder

The heterojunction construction can effectively regulate the carrier transport pathway. Ag₂Mo₂O₇/CoMoO₄ composite molybdate material was successfully synthesized by one step hydrothermal calcination method. The preparation method makes the contact of the two molybdate salts closer, forming a stable S-scheme heterojunction. Then SnS₂ was added under physical agitation to improve the mobility of photogenerated carriers. The excellent structure of the ternary composite catalyst was proved by morphology and element analysis. The electron transfer mechanism of the S-scheme heterojunction was studied by photoelectric chemical test and spectral analysis. Because of the successful construction of S-scheme heterojunction and the introduction of sensitizer SnS₂, the composite catalyst showed excellent hydrogen evolution performance (1599 μmol·g⁻¹·h⁻¹). This is because the S-scheme heterojunction and the sensitizer cooperatively promote the electron accumulation at the conduction band of CoMoO₄. This work will provide a new strategy for molybdate in a heterojunction construction scheme.     

Fabrication of the SnS2/ZnIn2S4 heterojunction for highly efficient visible light photocatalytic H2 evolution

A series of SnS₂/ZnIn₂S₄ (x-SS/ZIS) photocatalysts with different mass ratios of SnS₂ were prepared by a hydrothermal method. The resulted composites were used for photocatalytic hydrogen evolution under visible light excitation. All the SS/ZIS composites exhibited significantly enhanced photocatalytic activity for H₂ evolution. Obviously, the highest H₂ evolution rate of 769 μmol g^?1 h^?1 was observed over 2.5-SS/ZIS, which was approximately 10.5 times that of the ZnIn₂S₄ (73 μmol g^?1 h^?1). The enhanced photocatalytic performance was attributed to the successful construction of SnS₂/ZnIn₂S₄ heterojunctions, leading to rapid charge separation and fast transfer of the photo-generated electrons and holes under light irradiation. On the basis of PL, electrochemical impedance spectroscopy (EIS), photocurrent measurements and the H₂ evolution tests, a plausible photocatalytic mechanism was proposed.     

Green synthesis of Ag/Fe3O4/RGO nanocomposites by Punica Granatum peel extract: Catalytic activity for reduction of organic pollutants

The magnetically separable Ag/Fe₃O₄/RGO nanocomposites (NCs) were synthesized through a green method using Punica Granatum peel extract as a reducing and stabilizing agent. The total phenolic content (TPC) in the Punica Granatum peel extract and the ability of extract to scavenge the DPPH radical were measured and the results proved that the extract has the ability of reduction of Ag⁺ ions and graphene oxide (GO) to Ag nanoparticles (NPs) and reduced graphene oxide (RGO), respectively. Furthermore, the presence of phenolic compounds in the extract was confirmed using UV–Vis and FT-IR techniques. Deposition of Ag NPs on the surface of Fe₃O₄/RGO NCs was confirmed by color change from transparent to brown with maximum absorption at 418 nm which is due to surface plasmon resonance of Ag NPs. The crystalline nature of the Ag/Fe₃O₄/RGO NCs was identified utilizing XRD analysis. The catalytic activity of the green synthesized Ag/Fe₃O₄/RGO NCs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP), methylene blue (MB), methyl green (MG) and methyl orange (MO) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for the different types of dyes within few seconds. The morphology and catalytic activity of the Ag/Fe₃O₄/RGO NCs was compared with Ag/RGO and Ag/Fe₃O₄ NCs, which were synthesized using Punica Granatum peel extract. The results revealed that the unique synergistic effect of Ag NPs and immobilization over supporters of RGO and Fe₃O₄ magnetite composite assisted in the reduction of 4-NP, MB, MG and MO.     

Phytic acid-derived Co2-xNixP2O7-C/RGO and its superior OER electrocatalytic performance

A phytic acid-derived Co_2-xNi_xP₂O₇-C/RGO composite was designed and facilely synthesized, in which phytic acid acted as both a phosphoric source and carbon source. Both carbon derived from phytic acid and reduced graphene oxide (RGO) in composite, enhanced the conductivity and thus improve its electrocatalytical capability. As-synthesized Co_1.22Ni_0.78P₂O₇-C/RGO composite exhibited excellent oxygen evolution reaction (OER) catalytic performances: At the current density of 10 mA cm⁻², only a low overpotential of 283 mV and a small Tafel slope of 51 mV dec⁻¹ were observed. Good OER catalytic performance was retained even after 10 h continuously running at a constant voltage, which is even comparable to those of first-rate noble metal catalyst RuO₂. In addition, the performances of Co_2-xNi_xP₂O₇-C/RGO catalysts were also strongly dependent on Ni content.     

Nanocomposite of BiPO4 and reduced graphene oxide as an efficient photocatalyst for hydrogen evolution

Nanocomposites of BiPO₄ and reduced graphene oxide (BiPO₄/RGO) synthesized by hydrothermal method, hydrazine reduction, and UV-assisted photoreduction method were studied as photocatalysts for hydrogen evolution from ethanol aqueous solution under irradiation. The incorporation of RGO into BiPO₄ significantly enhanced the photocatalytic activity for H₂ evolution, and the photocatalytic activity increases in the order of BiPO₄/RGO-hydrothermal > BiPO₄/RGO-photoreduction > BiPO₄/RGO-hydrazine. The optimum proportion of GO is 2 wt% for all the samples prepared by different methods. The rate of H₂ production calculated for BiPO₄/RGO-hydrothermal (with 2 wt% GO) nanocomposite was about 306 μmol/h/g, which was almost 2 times as high as that for bare BiPO_4. The XRD, Raman and XPS characterization suggested that the original GO was successfully reduced to RGO. The more intimate contact between BiPO₄ and RGO, the higher photocurrent responses and the higher reduction degree of RGO was consistent with the higher photocatalytic performance.     

Monometallic,bimetallic, and trimetallic chalcogenide-based electrodes for electrocatalytic hydrogen evolution reaction

Cu₂CoSnS₄, Cu₂SnS₃, Cu₂CoS₄, Co₂SnS₃, Cu₂S, CoS₂, and SnS₂ were synthesized using a one-step solvent-free solid-phase approach. The surface structure, morphology, and composition were characterized using an X-ray diffractometer (XRD), Fourier-Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Photoelectron Spectroscopy (XPS). The characterizations reveal pure phase formation and porous morphology. Further, the Hydrogen evolution reaction was performed using Cu₂CoSnS₄, Cu₂SnS₃, Cu₂CoS₄, Co₂SnS₃, Cu₂S, CoS₂, and SnS₂-based electrodes. Amid all electrocatalysts, Cu₂CoSnS₄ shows an excellent hydrogen evolution reaction with a low overpotential of ?192.1 mV at ?10 mA/cm² in 0.5 M H₂SO₄. And higher current density. Cu₂CoSnS₄ also shows a lower Tafel slope of 98.6 mV/dec and charge transfer resistance than mono and bimetallic chalcogenide-based electrodes. The Cu₂CoSnS₄ exhibit very good stability for ～22 h at ?10 mA/cm² current density in 0.5 M H₂SO₄.     

Ternary Ni2P/reduced graphene oxide/g-C3N4 nanotubes for visible light-driven photocatalytic H2 production

Developing low cost co-catalysts is crucial for both fundamental research and practical application of g-C₃N₄. In this work, we prepared ternary Ni₂P/rGO/g-C₃N₄ nanotubes with different Ni₂P contents for visible-light-driven photocatalytic H₂ generation from triethanolamine aqueous solution. The optimal Ni₂P/rGO/g-C₃N₄ produced H₂ at a rate of 2921.9 μmol h⁻¹ g⁻¹, which is about 35, 16 and 9 times as large as that of g-C₃N₄, binary rGO/g-C₃N₄ and Ni₂P/g-C₃N₄, respectively. The apparent quantum efficiency of optimal Ni₂P/rGO/g-C₃N₄ was 5.6% at λ = 420 nm. We believe that the improved photocatalytic performance of Ni₂P/rGO/g-C₃N₄ originates from the synergistic effect of rGO as electron transfer medium and Ni₂P as reaction site, which is supported by photoelectrochemical and photoluminescence measurements. Cyclic experiment demonstrated an excellent stability of Ni₂P/rGO/g-C₃N₄. Moreover, we further studied the effect of other nickel-based compounds by replacing Ni₂P with NiS, Ni₃C, and Ni₃N, respectively. The order of the H₂-generation rate is Ni₂P/rGO/CNNT > NiS/rGO/CNNT > Ni₃C/rGO/CNNT > Ni₃N/rGO/CNNT, which could be reasonably explained based on Mott–Schottky plots. Our work reveals that Ni₂P can be used as a promising cocatalyst for photocatalytic H₂ evolution.     

Exposure of active sites in Mn–SnS2 nanosheets to boost hydrogen evolution reaction

Designing and synthesizing high-activity, durable, and low-cost catalysts for the electrochemically transformation of water to hydrogen are vitally important to future energy systems. Herein, a simple but effective strategy for manganese-metal-heteroatom doping is adopted to intrinsically elevate the electrocatalytic activities of SnS₂ nanosheets by a facile two steps hydrothermal-sulfurization approach. Electrocatalytic hydrogen evolution (HER) performance of Mn–SnS₂ nanosheets grown on 3D nickel foam (Mn–SnS₂/NF) is efficiently optimized since the dopants and defects endow the Mn–SnS₂/NF vast active sites. An overpotential as low as 71 mV is required to drive a current density of 10 mA/cm² with a low Tafel slope of 72 mV dec^?1 in alkaline environment (1 M KOH). In addition, the Mn–SnS₂/NF exhibits prominent stability in 1 M KOH electrolyte, which is an indispensable index for the potential HER electrocatalysts. The present work demonstrates that the heteroatom manganese doping strategy renders a meaningful route for synthesizing cost-efficient HER electrocatalysts in alkaline condition.     

Highly efficient visible-light-driven photocatalytic H2 production over a p−n Mn0.2Cd0.8S/NiCo2O4 heterojunction modified with Ni2P

In this work, the Mn_0.2Cd_0.8S/NiCo₂O₄ composite modified with Ni₂P as a co-catalyst was fabricated via a simple two-step hydrothermal method. The as-prepared ternary Mn_0.2Cd_0.8S/NiCo₂O₄/Ni₂P composite displayed excellent H₂ production performance. The ternary composite loaded with 5 wt% NiCo₂O₄ and 2 wt% Ni₂P obtained the optimal H₂ production performance of 24.47 mmol g^?1 h^?1 and a maximum AQE of 23.75%. The enhanced H₂ production activity was assigned firstly to efficient spatial charge separation through the p?n Mn_0.2Cd_0.8S/NiCo₂O₄ heterojunction and secondly to sufficient surface active sites provided by Ni₂P co-catalysts. This research provides a new approach to design effective ternary heterojunction.     

Facile preparation of SnS2 nanoflowers and nanoplates for the application of high-performance hybrid supercapacitors

In this work, the SnS₂ nanoflowers (SnS₂ NFs) were solvothermally prepared in the solvent of ethanol, while SnS₂ nanoplates (SnS₂ NPs) were obtained through the identical conditions except for the solvent of water. The flowers were assembled with numerous nanosheets with very thin thickness, and the NPs exhibited hexagonal shape. When used as the battery-type electrode material for supercapacitors, the SnS₂ NFs delivered a specific capacity of as high as 264.4 C g^?1 at 1 A g^?1, which was higher than the 201.6 C g^?1 of SnS₂ NPs. Furthermore, a hybrid supercapacitor (HSC) was assembled with the SnS₂ as positive electrode and activated carbon (AC) as negative electrode, respectively. The SnS₂ NFs//AC HSC exhibited a high energy density of 28.1 Wh kg^?1 at 904.3 W kg^?1, which was higher than the 24.2 Wh kg^?1 at 844.3 W kg^?1 of SnS₂ NPs//AC HSC. Especially, when the power density was enhanced to the highest value of 8666.8 W kg^?1, the NFs-based device could still hold 20.4 Wh kg^?1. In addition, both HSC devices showed an excellent cycling stability after 5000 cycles at 5 A g^?1. The present method is simple and can be extended to the preparation of other transition metal sulfides (TMSs)-based electrode materials with brilliant electrochemical performance for supercapacitors.     

Fabrication of hollow g-C3N4@α-Fe2O3/Co-Pi heterojunction spheres with enhanced visible-light photocatalytic water splitting activity

For the first time, g-C₃N₄@α-Fe₂O₃/Co-Pi heterojunctional hollow spheres were successfully fabricated via thermal condensation method followed by solvothermal and photo-deposition treatment, which showed excellent photocatalytical property. Except for the Z-scheme charge transfer between α-Fe₂O₃ and g-C₃N₄, the Co-Pi could further reduce the combination of photogenerated electrons and holes as a hole storage agent, resulting in remarkably enhanced visible-light photocatalytic water splitting activity with the H₂ production rate of 450 μmol h⁻¹g⁻¹, which is 15.7 times higher than that of g-C₃N₄. Moreover, the photocatalytic activity of the prepared ternary hollow photocatalysts showed almost no significant weakness after five cycles, which indicated their good performance stability. The as-prepared g-C₃N₄@α-Fe₂O₃/Co-Pi also possessed good activity for overall water splitting with the hydrogen production rate reaching 9.8 μmol h⁻¹g⁻¹. This synthesized g-C₃N₄@α-Fe₂O₃/Co-Pi composite is expected to be a promising candidate for water splitting.