Construction of g-C3N4/BCN two-dimensional heterojunction photoanode for enhanced photoelectrochemical water splitting

Two-dimensional heterojunction g-C₃N₄/BCN was constructed via thermal polymerization process. The formed two-dimensional heterostructure could enhance the interfacial contact area between BCN and porous g-C₃N₄ as well as shorten the photogenerated charge carriers transfer time and distance. The two-dimensional g-C₃N₄/BCN heterojunction photoanode shows enhanced photoelectrochemical (PEC) performance for water splitting under visible-light irradiation, which primarily originates from the improved charge transfer and separation, and prolonged lifetime of electrons. Under the visible light irradiation, the g-C₃N₄/BCN heterojunction sample yields a photocurrent density of ∼0.62 mA cm⁻² at 1.23 V vs. RHE, which is about eight times as many as that of CN (0.08 mA cm⁻²) electrode at the same conditions. In addition, the possible electron transfer model and mechanism of PEC water splitting for H₂ evolution have been discussed.     

A visible-light-driven heterojunction for enhanced photocatalytic water splitting over Ta2O5 modified g-C3N4 photocatalyst

The photocatalytic water splitting for generation of clean hydrogen energy has received increasingly attention in the field of photocatalysis. In this study, the Ta₂O₅/g-C₃N₄ heterojunctions were successfully fabricated via a simple one-step heating strategy. The photocatalytic activity of as-prepared photocatalysts were evaluated by water splitting for hydrogen evolution under visible-light irradiation (λ > 420 nm). Compared to the pristine g-C₃N₄, the obtained heterojunctions exhibited remarkably improved hydrogen production performance. It was found that the 7.5%TO/CN heterojunction presented the best photocatalytic hydrogen evolution efficiency, which was about 4.2 times higher than that of pure g-C₃N₄. Moreover, the 7.5%TO/CN sample also displayed excellent photochemical stability even after 20 h photocatalytic test. By further experimental study, the enhanced photocatalytic activity is mainly attributed to the significantly improve the interfacial charge separation in the heterojunction between g-C₃N₄ and Ta₂O₅. This work provides a facile approach to design g-C₃N₄-based photocatalyst and develops an efficient visible-light-driven heterojunction for application in solar energy conversion.     

Redox couple mediated charge carrier separation in g-C3N4/CuO photocatalyst for enhanced photocatalytic H2 production

Graphitic carbon nitride (g-C₃N₄) is one of the promising two-dimensional metal-free photocatalysts for solar water splitting. Regrettably, the fast electron-hole pair recombination of g-C₃N₄ reduces their photocatalytic water splitting efficiency. In this work, we have synthesized the CuO/g-C₃N₄ heterojunction via wet impregnation followed by a calcination method for photocatalytic H₂ production. The formation of CuO/g-C₃N₄ heterojunction was confirmed by XRD, UV–vis and PL studies. Notably, the formation of heterojunction not only improved the optical absorption towards visible region and also enhanced the carrier generation and separation as confirmed by PL and photocurrent studies. The photocatalytic H₂ production results revealed that CuO/g-C₃N₄ photocatalyst demonstrated the increased photocatalytic H₂ production rate than bare g-C₃N₄. The maximum H₂ production rate was obtained with 4 wt % CuO loaded g-C₃N₄ photocatalyst. Importantly, the rate of H₂ production was further improved by introducing simple redox couple Co²⁺/Co³⁺. Addition of Co²⁺ during photocatalytic H₂ production shuttled the photogenerated holes by a reversible conversion of Co²⁺ to Co³⁺ with accomplishing water oxidation. The effective shuttling of photogenerated holes decreased the election-hole pair recombination and thereby enhancing the photocatalytic H₂ production rate. It is worth to mention that the addition of Co²⁺ with 4 wt % CuO/g-C₃N₄ photocatalyst showed ∼7.5 and ∼2.0 folds enhanced photocatalytic H₂ production rate than bare g-C₃N₄/Co²⁺ and CuO/g-C₃N₄ photocatalysts. Thus, we strongly believe that the present simple redox couple mediated charge carrier separation without using noble metals may provide a new idea to reduce the recombination rate.     

Enhanced visible-light-assisted photocatalytic hydrogen generation by MoS2/g-C3N4 nanocomposites

A facile, one-pot, solvothermal synthesis of MoS₂ microflowers (S1) and the heterostructures MoS₂/g-C₃N₄ with varying ratios of 1:1 (S2), 1:2 (S3) and 1:3 (S4) exhibiting enhanced visible-light-assisted H₂ generation by water splitting has been reported. The compounds were thoroughly characterized by PXRD, FESEM, HRTEM, EDS, UV–vis and XPS techniques. FESEM and HRTEM analyses showed the presence of microflowers composed of nano-sized petals in case of pure MoS₂ (S1), while the MoS₂ microflowers covered with g-C₃N₄ nanosheets in case of MoS₂/g-C₃N₄ heterostructure, S4. XPS analysis of S2 showed the presence of 2H phase of MoS₂ with g-C₃N₄. The Eosin-Y/dye-sensitized visible-light-assisted photocatalytic investigation of the samples in the absence of any noble metal co-catalyst revealed very good water splitting activity of MoS₂/g-C₃N₄ heterostructure, S2 with hydrogen generation rate of 1787 μmol h⁻¹g⁻¹ which is about 6 and 40 times higher than pure MoS₂ and g-C₃N₄ respectively. The relatively higher catalytic activity of the heterostructure, S2 has been ascribed to the efficient spatial separation of photo-induced charge carriers owing to the synergistic interaction between MoS₂ and g-C₃N₄. A possible mechanism for the Eosin-Y-sensitized photocatalytic H₂ generation activity of MoS₂/g-C₃N₄ heterostructures has also been presented. The enhanced activity of S2 was further supported by fluorescence measurements. Thus, the present study highlights the importance of non-noble metal based MoS₂/g-C₃N₄ heterojunction photocatalysts for efficient visible-light-driven H₂ production from water splitting.     

Controlled photoinduced electron transfer from g-C3N4 to CuCdCe-LDH for efficient visible light hydrogen evolution reaction

Ample visible-light response and efficient charge transfers in semiconductor heterojunction are still enslaved to the limited photocatalytic water splitting. In most cases, the rational design of hybrid composites tune in atomic level interaction led to remarkable stability and superior activity. Here, this work is a systematic investigation of metal ion substitution in the LDH and LDH/g-C₃N₄ hybrid composites for hydrogen evolution reaction (HER) under visible light. The construction of heterostructure not only facilitates the charge separation and transfer owing to the formed heterojunction through band gap engineering and tunable optical properties which are inherited from morphology of as grown CuCdCe-LDH over the exfoliated g-C₃N₄ but also provides plenty of surface active sites due the increased surface area photostability. The CuCdCe-LDH/g-C₃N₄ exhibits superior HER rate of 3.5 mmolg^?1h^?1 with AQY of 5.78% over their binary counterparts. The density functional theory calculations also suggest that the HER activity of CuCdCe-LDH is substantially enhanced by coupling with g-C₃N₄ the electrochemical results leading to high photocurrent response. The high photocatalytic activity of the composite was due to efficient photoexcited charge transfer process and the synergistic effect between CuCdCe-LDH and g-C₃N₄. These finding will open scopes for designing inexpensive high performance materials for broad applications of photocatalytic energy conversion.     

Construction of Au/g-C3N4/ZnIn2S4 plasma photocatalyst heterojunction composite with 3D hierarchical microarchitecture for visible-light-driven hydrogen production

In this paper, a novel Au/g-C₃N₄/ZnIn₂S₄ plasma photocatalyst heterojunction composite with 3D hierarchical microarchitecture has been successfully constructed by integrating Au/g-C₃N₄ plasmonic photocatalyst composite with 3D ZnIn₂S₄ nanosheet through a simple hydrothermal process. The Au nanoparticles were firstly anchored on the surface of pristine g-C₃N₄ material to get Au/g-C₃N₄ plasmonic photocatalyst. Ascribing to the surface plasmon resonance of Au nanoparticles, the obtained Au/g-C₃N₄ plasmonic photocatalyst shows a significant improved photocatalytic activity toward hydrogen production from water with visible light response comparing with pristine g-C₃N₄. Further combining Au/g-C₃N₄ plasmonic photocatalyst with 3D ZnIn₂S₄ nanosheet to construct a heterojunction composite. Owing to the synergistic effect of the surface plasmon resonance of Au nanoparticles in Au/g-C₃N₄ and the heterojunction structure in the interface of Au/g-C₃N₄ and ZnIn₂S₄, the prepared Au/g-C₃N₄/ZnIn₂S₄ plasma photocatalyst heterojunction composite shows an excellent photocatalytic activity toward hydrogen production from water with visible light response, which is around 7.0 and 6.3 times higher than that of the pristine C₃N₄ and Znln₂S₄ nanosheet, respectively. The present work might provide some insights for exploring other efficient heterojunction photocatalysts with excellent properties.     

Heterostructured thin LaFeO3/g-C3N4 films for efficient photoelectrochemical hydrogen evolution

The deposition of LaFeO₃ at the surface of a graphitic carbon nitride (g-C₃N₄) film via magnetron sputtering followed by oxidation for photoelectrochemical (PEC) water splitting is reported. The LaFeO₃/g-C₃N₄ film was investigated by various characterization techniques including SEM, XRD, Raman spectroscopy, XPS and photo-electrochemical measurements. Our results show that the hydrogen production rate of a g-C₃N₄ film covered by a LaFeO₃ film, exhibiting both a thickness of ca. 50 nm, is of 10.8 μmol h⁻¹ cm⁻² under visible light irradiation. This value is ca. 70% higher than that measured for pure LaFeO₃ and g-C₃N₄ films and confirms the effective separation of electron-hole pairs at the interface of LaFeO₃/g-C₃N₄ films. Moreover, the LaFeO₃/g-C₃N₄ films were demonstrated to be stable and retained a high activity (ca. 70%) after the third reuse.     

PtS2/g-C3N4 van der Waals heterostructure: A direct Z-scheme photocatalyst with high optical absorption,solar-to-hydrogen efficiency and catalytic activity

Using two-dimensional semiconductors to build heterojunction as photocatalyst for water splitting is an important green and clean energy technology and has wide development prospects. Here, the monolayered PtS₂ and g-C₃N₄ are used to build the direct Z-scheme van der Waals (vdW) heterostructure, and the structure, electrical, Bader charge, optical properties and solar-to-hydrogen efficiency are calculated in detail through first-principle calculations. The direct Z-scheme PtS₂/g-C₃N₄ vdW heterostructure has an inherent type-II band alignment that enables it to reduce the photogenerated carriers aggregation, and it also possesses a decent band edge position to fully induce the redox reactions of decomposed water. The charge density shows that PtS₂ monolayer is negatively charged while g-C₃N₄ monolayer is positively charged, and the interface potential drop of PtS₂/g-C₃N₄ vdW heterostructure forms a built-in electric field with the direction from g-C₃N₄ to PtS₂. The PtS₂/g-C₃N₄ vdW heterostructure has suitable optical property, outstanding solar-to-hydrogen efficiency, high catalytic activity and thus a promising application prospect for photocatalytic water splitting.     

Rational design of plasmonic Ag@CoFe2O4/g-C3N4 p-n heterojunction photocatalysts for efficient overall water splitting

Highly efficient and direct photocatalytic H₂ evolution from water via water splitting without using sacrificial reagents is a challenging approach to convert solar energy into renewable and storable chemical energy. Herein, by amalgamating the architecture recommendations and energy band engineering principles into the design formulation, a novel Ag@CoFe₂O₄/g-C₃N₄ plasmonic p-n heterojunction photocatalytic system is designed and constructed for the first time. The Ag@CoFe₂O₄/g-C₃N₄ photocatalyst so designed, under the illumination of the visible-light (λ > 420 nm), produced H₂ and O₂ in 2:1 stoichiometric amount at the rates of 335 μmol h^?1 and 186 μmol h^?1, respectively, with an apparent quantum yield reaching 3.35% at 420 nm, demonstrating that Ag@CoFe₂O₄ dimer colloids are responsible for oxidation and g-C₃N₄ for reduction. Moreover, in the presence of triethanolamine, the apparent quantum yield achieved by Ag@CoFe₂O₄/g-C₃N₄ is 16.47% with hydrogen produced at the rate 3.5 times higher than the CoFe₂O₄/g-C₃N₄ heterojunction photocatalyst with AQY of 5.49%. The combination of Ag plasmonic effect and internal electric field established at the interface of p-type CoFe₂O₄ and n-type g-C₃N₄ boosts the separation efficiency of photoexcitons from CoFe₂O₄ to g-C₃N₄, extending the visible-light absorption capacity of the systems. The generation of optimum amount of defects like oxygen vacancies at the p-n heterojunction interface due to the structural distortion of CoFe₂O₄ also plays a prominent photocatalytic enhancement by providing active sites for the adsorption of water molecules for the light driven catalytic reactions. Our work introduces a potential avenue to design efficient photocatalysts by constructing several other suitable p-n heterojunction semiconductor photocatalysts toward practical application in solar energy conversion.     

Preparation,structure and application of g-C3N4/BiOX composite photocatalyst

Graphite-like carbon nitride (g-C₃N₄) has attracted great attention for pollutant degradation and clean energy production. The heterojunctions of bismuth halide (BiOX, X = Cl, Br, I) and g-C₃N₄ are proposed to overcome the shortcomings of the g-C₃N₄ photocatalyst, such as low charge separation rate and high charge recombination rate. This review paper systematically discusses the progress in synthesis, structure, and applications of heterojunction photocatalytic composites made of g-C₃N₄ and BiOX based on the understanding of their photocatalytic reaction mechanism. We clarify and summarize structural mechanisms of a single and compound semiconductor to reveal the factors that affect photocatalytic performances. We discuss and compare advantages and disadvantages of versatile preparation processes. Particularly, we focus on the understanding of the structure and characteristics of type II, Z-type, n-n, and p-n heterojunctions and their applications, specifically in pollutant degradation, H₂ production by water splitting, CO₂ reduction, and medical sterilization. The future prospects of g-C₃N₄/BiOX composites are also discussed from aspects of their preparation, application, and research methods. This work may offer a good avenue and data reference to develop novel g-C₃N₄ photocatalytic materials to meet the ever-increasing environmental pollution and energy shortage.     

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.     

Two-dimensional g-C6N6/SiP-GaS van der Waals heterojunction for overall water splitting under visible light

The energy crisis caused by the decrease of fossil fuels and the environmental pollution problems related to combustion can be resolved through the green technology of photocatalytic water splitting to produce hydrogen. A novel g-C₆N₆/SiP-GaS van der Waals heterojunction is designed and its structural, optoelectronic and photocatalytic properties are systematically investigated by using the first-principles method. The results indicate that the g-C₆N₆/SiP-GaS heterojunction is a type-Ⅱ heterojunction and the band edge straddles the redox potential of water splitting. The g-C₆N₆/SiP-GaS heterojunction exhibits good optical absorption in the visible-light range. It is worth noting that the optoelectronic properties and thermodynamic feasibility of the heterojunction can be modulated by the biaxial strain. Interestingly, all the optical absorption, OER and HER can be effectively improved under the strain of ?4%. The work supplies a strategy for the design and making of novel heterojunction for a highly effective photocatalyst in water splitting.     

Synthesis of g-C3N4/WO3-carbon microsphere composites for photocatalytic hydrogen production

In this paper, a g-C₃N₄/WO₃-carbon microsphere composite-based photocatalyst was successfully prepared by a one-pot thermal synthesis method for sunlight driven decomposition of water to produce hydrogen. The results show that the g-C₃N₄/WO₃-carbon microspheres had better photocatalytic properties and stability. Under visible light and sunlight irradiation, the hydrogen production efficiency of the photocatalytic decomposition of water was 107.75 times and 70.54 times greater than that of pure g-C₃N₄, respectively. The experimental and characterization results show that g-C₃N₄ and WO₃ formed a Z-scheme heterojunction on the surface of the g-C₃N₄/WO₃-carbon microsphere composite-based photocatalyst. Carbon microspheres modified on g-C₃N₄ nanosheets and WO₃ had good conductivity and promoted the transfer of photogenerated electrons in g-C₃N₄ nanosheets. The addition of carbon microspheres increased the specific surface area of the composite photocatalyst. The g-C₃N₄/WO₃-carbon microsphere composite-based photocatalyst showed strong adaptability to the fluctuating light intensity, providing feasibility for industrialized mass production.     

1D/2D carbon-doped nanowire/ultra-thin nanosheet g-C3N4 isotype heterojunction for effective and durable photocatalytic H2 evolution

It is still challenging to design effective g-C₃N₄ photocatalysts with high separation efficiency of photo-generated charges and strong visible light absorption. Herein, a simple, template-free and “bottom-up” strategy has been developed to prepare 1D/2D g-C₃N₄ isotype heterojunction composed of carbon-doped nanowires and ultra-thin nanosheets. The ethanediamine (EE) grafted on melamine ensures the growth of 1D g-C₃N₄ nanowires with high carbon doping, and the ultra-thin g-C₃N₄ nanosheets were produced through HCl-assisted hydrothermal strategy. The apparent grain boundary between 2D nanosheets and 1D carbon-doped nanowires manifested the formation of the isotype heterojunction. The built-in electric field provide strong driving force for photogenerated carriers separation. Meanwhile, the doping carbon in g-C₃N₄ nanowires promotes visible light absorption. As a result, the photocatalytic H₂ evolution activity of 1D/2D g-C₃N₄ isotype heterojunction is 8.2 time that of the pristine g-C₃N₄, and an excellent stability is also obtained. This work provides a promising strategy to construct isotype heterojunction with different morphologies for effective photocatalytic H₂ evolution.     

Hierarchical TiO2 spheroids decorated g-C3N4 nanocomposite for solar driven hydrogen production and water depollution

A novel hierarchical TiO₂ spheroids embellished with g-C₃N₄ nanosheets has been successfully developed via thermal condensation process for efficient solar-driven hydrogen evolution and water depollution photocatalyst. The photocatalytic behaviour of the as-prepared nanocomposite is experimented in water splitting and organic pollutant degradation under solar light irradiation. The optimal ratio of TiO₂ spheroids with g-C₃N₄ in the nanocomposite was found to be 1:10 and the resulting composite exhibits excellent photocatalytic hydrogen production of about 286 μmol h^?1g^?1, which is a factor of 3.4 and 2.3 times higher than that of pure TiO₂ and g-C₃N₄, respectively. The outstanding photocatalytic performance in this composite could be ascribed as an efficient electron-hole pair's separation and interfacial contact between TiO₂ spheroids with g-C₃N₄ nanosheets in the formed TiO₂/g-C₃N₄ nanocomposite. This work provide new insight for constructing an efficient Z-scheme TiO₂/g-C₃N₄ nanocomposites for solar light photocatlyst towards solar energy conversion, solar fuels and other environmental applications.     

Montmorillonite-hybridized g-C3N4 composite modified by NiCoP cocatalyst for efficient visible-light-driven photocatalytic hydrogen evolution by dye-sensitization

The photocatalytic hydrogen evolution performance of g-C₃N₄ was enhanced via the hybridization with montmorillonite (MMT) and using NiCoP as cocatalyst. The highest hydrogen-evolution rate from water splitting under visible-light irradiation observed over MMT/g-C₃N₄/15%NiCoP was 12.50 mmol g⁻¹ h⁻¹ under 1.0 mmol L⁻¹ of Eosin Y-sensitization at pH of 11, which was ∼26.0 and 1.6 times higher than that of MMT/g-C₃N₄ (0.48 mmol g⁻¹ h⁻¹) and g-C₃N₄/15%NiCoP (7.69 mmol g⁻¹ h⁻¹). The apparent quantum yield at 420 nm reached 40.3%. The remarkably improved photocatalytic activity can be ascribed to the increased dispersion of g-C₃N₄ layers, staggered conduction band potentials between g-C₃N₄ and NiCoP, as well as the electrostatic repulsion originated from negatively charged MMT. This work demonstrates that MMT can be an outstanding support for the deposition of catalytically active components for photocatalytic hydrogen production.     

Switching charge transfer of g-C3N4/BiVO4 heterojunction from type II to Z-scheme via interfacial vacancy engineering for improved photocatalysis

Constructing type II heterojunction is an efficient strategy to enhance the light absorption and promote the charge transport. However, the improvement effect is limited by the decreased redox ability of charge carriers. The rational design of heterojunction from type II to Z-scheme is expected to overcome this obstacle. Herein, we demonstrate that the introduction of interfacial oxygen vacancies (OVs) can switch charge transfer of g-C₃N₄/BVO heterojunction from type II to Z-scheme. The interfacial OVs acted as the reactive center of charge carriers to quench the electrons of BVO and holes of g-C₃N₄, thereby promoting charge separation and migration. As a result, the interfacial OVs mediated Z-scheme g-C₃N₄/BVO heterojunction kept the strong oxidation/reduction potential of two single-component photocatalysts thereby significantly enhancing the photodegradation of tetracycline and CO₂ photoreduction. The kinetic constant of tetracycline degradation on the optimal g-C₃N₄/BVO-20 sample was 2.04-fold and 2.29-fold higher than those on g-C₃N₄ nanosheets and pure BVO, respectively. This work provides a feasible strategy by the interfacial vacancy engineering of heterojunction for enhanced photocatalysis.     

Construction of heterostructured g-C3N4@TiATA/Pt composites for efficacious photocatalytic hydrogen evolution

Construction of heterostructured photocatalysts is a feasible method for improving hydrogen production from water splitting because of its good charge transport efficiency. Herein, we coupled the Ti-MOFs (TiATA) with metal-free graphitic carbon nitride (g-C₃N₄) to synthesize composites, g-C₃N₄@TiATA, in which a heterostructure was formed between g-C₃N₄ and TiATA. The establishment of heterojunctions not only broadens the light absorption range of g-C₃N₄@TiATA (490 nm) by contrast with g-C₃N₄ (456 nm), but also greatly accelerates charge migration. Photocatalytic studies present that the construction of heterostructure steering the charges flow from g-C₃N₄ to TiATA and then delivery to the cocatalyst of Pt nanoparticles, exhibiting an impressively photocatalytic hydrogen production rate (265.8 μmol·h⁻¹) in assistance of 300 W Xenon lamp, which is about 3.4 times as much as g-C₃N₄/Pt.     

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.     

Fabrication of P-doped Co9S8/g-C3N4 heterojunction for excellent photocatalytic hydrogen evolution

Developing lower-cost and higher-efficient photocatalysts is still a major challenge for the solar to hydrogen energy conversion by photocatalytic water splitting. Herein, P-doped Co₉S₈ (P–Co₉S₈) was synthesized by a hydrothermal process using low-cost RP as raw material, and then P–Co₉S₈ was employed to construct heterojunction with g-C₃N₄ via a mechanical-mixing method. Investigation shows that P–Co₉S₈ can not only improve the electrical conductivity and surface area of the composite, but also can lower the over-potential of H₂ evolution, leading to an enhanced H₂ evolution kinetics. The H₂ evolution rate of resultant 25% P–Co₉S₈/g-C₃N₄ reached 4362 μmol g⁻¹ h⁻¹ under UV and visible light, being nearly 121.2 times higher than that of g-C₃N₄. The charge transfer between P–Co₉S₈ and g-C₃N₄ follows the Type-I route based on the photoelectrochemical analysis, leading to more electrons on the conduction band of P–Co₉S₈ to participate the H₂ evolution processes. This work provides a new way for preparation of P-doped sulfides with potential applications in the field of photocatalysis.