Metal-free Photocatalyst Research Articles

A novel phenolic pyrylium-based porous organic polymer promotes solar-driven photocatalytic CO2 reduction

Research on ionic porous organic polymers (iPOPs) for photocatalytic carbon dioxide (CO2) reduction has shown promising progress over the past decade, but improving their catalytic performance in CO2 reduction remains a challenge. In this work, neutral monomer 2,6-dimethyl-γ-pyrone (DMPy) is employed into iPOPs (Py-POPOH) via Aldol condensation, where acidic conditions could not only catalyze the reaction, but also convert DMPy from quinoid structure to phenol-based pyrylium. The cationic sites facilitate the electrostatic adsorption of CO2, while the phenol structures aid in electron delocalization across the pyrylium, thereby broadening the photoresponse range and increasing the charge separation efficiency. Moreover, the phenolic hydroxyl intensifies the interaction with CO2 through hydrogen bonds, leading to improved photocatalytic performance. The resultant Py-POPOH exhibits significant advancement in light absorption, extending to 792 nm, and achieves a high CO2 to CO conversion rate of 237.75 µmol g-1h−1 as metal-free photocatalysts, almost 6 times higher than that of phenol-free structure. This result demonstrates the potential of iPOPs in improving photocatalytic performance, and provides a way to further improve the design of photocatalysts.

Synergistic N-heterocyclic carbene and C2N integration for efficient and selective metal-free photocatalytic CO reduction to C2H5OH

In the pursuit of sustainable and highly efficient catalysts for the reduction of CO to valuable multi-carbon fuels, this study presents a novel metal-free catalyst, C/C2N, created by integrating N-heterocyclic carbene (NHC) into a C2N monolayer. Utilizing density functional theory, we demonstrate that this integration effectively addresses the individual limitations of C2N and NHC, neither of which can stably adsorb CO molecules on their own. The synergistic effect of C2N and NHC facilitates distinct CO adsorption energies on the C2N surface (−0.08 eV) and at the NHC site (−0.83 eV), leading to an exceptionally low C–C coupling energy barrier of 0.41 eV, surpassing traditional metal-based catalysts. Computational results reveal that C/C2N exhibits outstanding activity and selectivity in reducing CO to C2H5OH, with a remarkably low free energy barrier of only 0.34 eV, further reducible to 0.20 eV under alkaline conditions. Furthermore, the integration of NHC into the C2N monolayer markedly narrows its band gap, enhancing visible light absorption and optimizing band edge positions, suggesting its potential for visible-light-driven reactions. Our findings establish C/C2N as an effective and selective metal-free photocatalyst with a notably low C–C coupling energy barrier, offering a novel avenue for CO conversion to multi-carbon fuels.

Synergy of P doping and crystallinity modulation in carbon nitride for enhancing photocatalytic uranyl reduction

Doping modification is a useful way to promote the catalytic activity of carbon nitride (CN). However, most doped CNs have lower structural symmetry and several edge defects, which hinder the transfer of charge carriers. This work reports a P-doped crystalline carbon nitride (crystalline PCN) for the efficient photoreduction of uranyl. The thermal polymerization and salt post-treatment convert the amorphous PCN into crystalline PCN. Compared to the pristine CN, the crystalline PCN has over 1620 % higher activity for uranyl (U(VI)) reduction, reaching a 97.8 % reduction rate in 60 min. Furthermore, the 2-PCN shows excellent stability and a U(VI) removal efficiency >85.7 % in the pH range of 5–8. Characterization analysis reveal that both the P doping and crystalline modulation do not obviously change their morphology, light absorption property and energy band structure, but markedly promote the delocalization of electrons around the doped P atoms, thereby severely inhibit direct electron-hole recombination. Thus, the more efficient separation of charge carriers generates more reactive specials to participate in the photocatalytic uranyl reduction reaction. This study demonstrates a dual-modification strategy for the rational synthesis of highly active metal-free CN-based photocatalysts for uranyl reduction.

Photocatalytic activity of selenium decorated graphitic carbon nitride nanocomposites for dye Industries wastewater remediation

In situ selenium-doped graphitic carbon nitride, also known as Se-g-C3N4(SCN), were created in the current study by employing inexpensive urea and selenium metal powder as precursor materials. SEM (scanning electron microscopy), XRD (X-ray diffraction), FTIR (Fourier-transform infrared spectroscopy), as well as TEM (transmission electron microscopy) techniques were utilized to describe the morphological characteristics, optical characteristics, and structural characteristics of the treated photocatalyst. Because of its potential use in photocatalytic environmental pollution remediation, graphitic carbon nitride (g-C3N4), a metal-free photocatalyst, has received a lot of interest. This work not only offers a straightforward method to improve the photocatalytic performance for g-C3N4 but also creates a new path for the logical preparation of efficient polymeric photocatalysts. The results demonstrate that does not alter the crystalline structure of the sample but instead increases the surface area of g-C3N4 by dispersing it widely. Three different photocatalytic composites of g-C3N4 and SeNPs in the mass ratios of 1:1, 2:1, and 3:1, denoted SCN1, SCN2, and SCN3, were created for the methylene blue (MB) and methyl orange (MO) photodegradation. The combined photocatalytic degradation rate of MB after 150 min in visible light (500–800 nm) was 52.4% for g-C3N4, 75.4% for SCN1, 87.8% for SCN2, and 81.3% for SCN3. For methyl orange, the photocatalytic activity of produced materials was also investigated. The analysis's outcome reveals astonishing deterioration values were 45.6% for g-C3N4, SCN1 (62.5%), SCN2 (74.1%), and SCN3(68.5%), respectively. The synthesized photocatalyst offers great potential for the effective removal of dye industeries wastewater remediation.

Electrosynthesis of an Improbable Directly Bonded Phosphorene-Fullerene Heterodimensional Hybrid toward Boosted Photocatalytic Hydrogen Evolution.

Phosphorene and fullerene are representative two-dimensional (2D) and zero-dimensional (0D) nanomaterials respectively, constructing their heterodimensional hybrid not only complements their physiochemical properties but also extends their applications via synergistic interactions. This is however challenging because of their diversities in dimension and chemical reactivity, and theoretical studies predicted that it is improbable to directly bond C60 onto the surface of phosphorene due to their strong repulsion. Here, we develop a facile electrosynthesis method to synthesize the first phosphorene-fullerene hybrid featuring fullerene surface bonding via P-C bonds. Few-layer black phosphorus nanosheets (BPNSs) obtained from electrochemical exfoliation react with C60 2- dianion prepared by electroreduction of C60, fulfilling formation of the "improbable" phosphorene-fullerene hybrid (BPNS-s-C60). Theoretical results reveal that the energy barrier for formation of [BPNS-s-C60]2- intermediate is significantly decreased by 1.88 eV, followed by an oxidization reaction to generate neutral BPNS-s-C60 hybrid. Surface bonding of C60 molecules not only improves significantly the ambient stability of BPNSs, but also boosts dramatically the visible light and near-infrared (NIR) photocatalytic hydrogen evolution rates, reaching 1466 and 1039 μmol h-1 g-1 respectively, which are both the highest values among all reported BP-based metal-free photocatalysts.

Reduction of the photogenerated electron transport path by modulating the conduction band region to achieve the highest lignin β–O–4 bond photocleavage efficiency under xenon excitation

Photocracking of lignin β–O–4 bonds is a green approach for the high-value modification of lignin. Graphitic carbon nitride (g-C3N4) that can photocleave the β–O–4 bond is presently the only stable, metal-free photocatalyst owing to the residual metal ions generated due to photocorrosion of metal sulfides. Herein, g-C3N4 with a N–C3 vacancy structure is prepared by etching site–engineering strategy based on the protection of C–N=C structure by chlorine atom. The N–C3 vacancy structure can reduce the transport path of the photogenerated electrons by tuning the conduction band (CB) region to the edge of the photocatalyst, which impedes the critical complexation of the photogenerated electron–hole pairs and enhances the photoelectric conversion efficiency five-fold. Combined with the unique chemisorption capacity (137.82 kJ/mol) of N–C3 vacancies for oxygen, the g-C3N4 photocatalysts with N–C3 vacancy structure can generate 9.6-fold higher superoxide radicals and 13-fold higher lignin β–O–4 bond photocleavage efficiency lignin compared with untreated g-C3N4. Based on the reaction enthalpy changes and free energies investigated through simulations, a route of lignin Cα–Cβ bonds being oxidized and dehydrogenated twice by photogenerated cavities is proposed for the first time. This work reveals the relation between the properties of g-C3N4 and the photocleavage efficiency of lignin β–O–4 bonds.

Promoted Hydrogen Peroxide Production from Pure Water on g-C3N4 with Nitrogen Defects Constructed through Solvent-Precursor Interactions: Exploring a Complex Story in Piezo-Photocatalysis.

Hydrogen peroxide (H2O2) production via oxygen (O2) reduction reaction (ORR) in pure water (H2O) through graphitic carbon nitrides (g-C3N4)-based piezo-photocatalysts is an exciting approach in many current studies. However, the low Lewis-acid properties of g-C3N4 limited the catalytic performance because of the low O2 adsorption efficacy. To overcome this challenge, the interaction of g-C3N4 precursors with various solvents are utilized to synthesize g-C3N4, possessing multiple nitrogen-vacant species via thermal shocking polymerization. These results suggest that the lack of nitrogen in g-C3N4 and the incident introduction of oxygen-functional groups enhance the Lewis acid-base interactions and polarize the g-C3N4 lattices, leading to the enormous enhancement. Furthermore, the catalytic mechanisms are thoroughly studied, with the formation of H2O2 proceeding via radical and water oxidation pathways, in which the roles of light and ultrasound are carefully investigated. Thus, these findings not only reinforce the potential view of metal-free photocatalysts, accelerating the understanding of g-C3N4 working principles to generate H2O2 based on the oxygen reduction and water oxidation reactions, but also propose a facile one-step way for fabricating highly efficient and scalable photocatalysts to produce H2O2 without using sacrificial agents, pushing the practical application of in situ solar H2O2 toward real-world scenarios.

Photocatalytic NOx removal and self-cleaning performance of polymeric carbon nitride functionalized alkali-activated slag composites

Alkali-activated slag (AAS) materials have been extensively investigated and employed for the photocatalytic coating incorporation due to their favorable binding property and low carbon emissions. However, the effects of photocatalysts on the microstructure and mechanical performance of AAS composites remain controversial, which have a significant impact on the durability of the photocatalytic composites in the real-life service environment. Herein, polymeric carbon nitride (PCN), as a metal-free photocatalyst, was mixed with AAS materials to prepare photocatalytic composites for nitrogen oxide (NOx) removal and surface self-cleaning. The PCN dosage effects on hydration products, microstructure, as well as mechanical and photocatalytic performances of the photocatalytic AAS composites were systematically studied. The results show that while hydration product formations are hindered by the PCN addition, its presence contributes to the carbonization of AAS composites. Additionally, due to the PCN microfiller effect, the microstructure of AAS composites is improved with the PCN addition, and the compressive strength of AAS composites becomes stronger as PCN dosage increases from 0 % to 6 %. The photocatalytic NOx removal and self-cleaning performances of PCN-added AAS composites are firstly increased and then decreased with the PCN addition. These findings provide the theoretical basis and technical support for PCN-added AAS composites application which satisfies the requirement for a sustainable and low carbon footprint future.

Integrating Multipolar Structures and Carboxyl Groups in sp2-Carbon Conjugated Covalent Organic Frameworks for Overall Photocatalytic Hydrogen Peroxide Production.

The direct production of hydrogen peroxide (H2O2) through photocatalytic reaction via H2O and O2 is considered as an ideal approach. However, the efficiency of H2O2 generation is generally limited by insufficient charge and mass transfer. Covalent organic framework (COFs) offer a promising platform as metal-free photocatalyst for H2O2 production due to their potential for rational design at the molecular level. Herein, we integrated the multipolar structures and carboxyl groups into COFs to enhance the efficiency of photocatalytic H2O2 production in pure water without any sacrificial agents. The introduction of octupolar and quadrupolar structures, along with an increase of molecular planarity, created efficient oxygen reduction reaction (ORR) sites. Meanwhile, carboxyl groups could not only boost O2 and H2O2 movement via enhancement of pore hydrophilicity, but also promote proton conduction, enabling the conversion to H2O2 from ⋅O2 -, which is the crucial intermediate product in H2O2 photocatalysis. Overall, we demonstrate that TACOF-1-COOH, consisting of optimal octupolar and quadrupolar structures, along with enrichment sites (carboxyl groups), exhibited a H2O2 yield rate of 3542 μmol h- 1 g-1 and a solar-to-chemical (SCC) efficiency of 0.55 %. This work provides valuable insights for designing metal-free photocatalysts for efficient H2O2 production.

Nitrogen vacancy-modified g-C3N4 nanosheets controlled by deep eutectic solvents for highly efficient photocatalytic atrazine degradation: Non-radical dominated holes oxidation

Metal-free photocatalysts like graphitic carbon nitride (g-C3N4) can have their electronic structures altered by vacancy defect engineering, greatly increasing their catalytic activity. Here, we have synthesized nitrogen vacancy mediated carbon nitride (DCNA) modified by deep eutectic solvents for the first time, DCNA showed 4.93-fold improvement compared to pristine g-C3N4 towards photocatalytic degradation of atrazine (ATZ). Besides, we have revealed the role of photogenic holes as the main active species for the photocatalytic degradation of ATZ. This improvement is attributed to the increased nitrogen vacancy, which increases the adsorption of N–H on the ATZ side chain, accelerates the process of photoelectron and hole separation, and allows more holes to participate in ATZ degradation. Moreover, the wheat growth toxicity test significantly reduced the degradation byproducts’ toxicity. This study provides an effective method for preparing environmentally friendly metal-free photocatalysts with high catalytic performance.

Fully conjugated radical-doped COF for near-infrared photothermal conversion, C-3 thiocyanation of indoles and oxidative coupling of amines

Radical-doped covalent organic frameworks (COFs) have received much interest as it confers additional functions such as photomodulated electrical conductivity, magnetism, and photochromism. Such COFs are relatively underexplored, however, mainly due to the lack of suitable highly photoactive building blocks. Herein, a rare radical-doped fully conjugated COF (PDI-COF) was rationally designed and prepared by incorporating photoactive perylenediimides (PDIs) into its framework. Characterization of the product PDI-COF not only confirmed its porous and stable skeleton, but also revealed the radical derived from photoinduced electron transfer between the PDI and electron donor. The fully conjugated and radical-doped characteristics enable the effective realization of near-infrared photothermal conversion in this COF. Moreover, this radical-doped COF can efficiently generate superoxide radical anions under light irradiation, which promote the photocatalytic C-3 thiocyanation of indoles and the oxidative coupling of amines in high yield and good recyclability at room temperature and without additives. This study demonstrates that introducing a photoactive organic dye into a COF is an effective approach to photothermal conversion materials and metal-free porous photocatalysts for application in photothermal therapy and photocatalytic organic synthesis.

Tailoring a decatungstate-incorporated metal-organic framework for light-driven [3+2] cyclization of phenols with olefins

Photocatalytic oxidative [3+2] cycloaddition of phenol-olefin is an economy and green strategy to synthesize 2,3-Dihydrobenzofurans (2,3-DHBs) compared with the thermal catalysis with noble metals under harsh conditions. Thus, it is urgent to design noble metal-free heterogeneous photocatalyst that combined single-electron transfer (SET) and hydrogen-atom transfer (HAT) dual function. Decatungstate [W10O32]4− is considered as an ecofriendly photocatalyst for HAT and SET, but it is commonly used in homogeneous catalysis. Herein, we report CuW10-TIPA as a white-light-activated heterogeneous photocatalyst for synthesizing 2,3-dihydrobenzofurans via [3+2] cycloaddition of phenols with olefins, a crucial step in relevant pharmaceutical structural motifs. The coordination bonds between Cu(I) and TIPA, strong H-bonds between TIPA and [W10O32]4− and anion∙∙∙π interactions between [W10O32]4− and TIPA dramatically promote the separation of photoinduced electron-hole and facilitate the charge transfer among each component. Our approach is characterized by its mildness, scalability, and recyclability. We delve into the discussion on [W10O32]4− anions-mediated C-H bond activation via the HAT pathway, with the cooperation of the photosensitizer TIPA and Cu(I), which enhances absorption in the visible region and narrows the energy band.

Construction of metal-free dual S-scheme heterojunction photocatalysts by rational band alignment for efficient hydrogen evolution

Designing ternary heterojunction photocatalysts is regarded as a compelling approach to attain exceptional photocatalytic activity. However, they always suffer from poor interfacial contact and unclear charge transfer pathways. Herein, a metal-free dual S-scheme heterojunction photocatalyst comprised of black phosphorus (BP), carbon nitride (CN), violet phosphorus (VP) was designed by electrostatic self-assembly. The non-metallic feature of the BPCNVP heterostructure facilitates to form strong interfacial contact by coordinating active P sites in VP and BP with N atoms in CN. Notably, a definite dual S-scheme heterojunction configuration is achieved by rational band alignment of VP and BP, respectively, which significantly boosts the driving force for charge separation. The BPCNVP heterostructure exhibited a hydrogen evolution rate of 1669μmol h-1g−1 with excellent stability, surpassing most reported metal-free photocatalysts. This work demonstrates that the design of dual S-scheme heterojunction by metal-free materials provides valuable insights into the intricate reaction mechanism of ternary heterojunction photocatalysts.

Photothermal-enabled metal-free polyfuran photocatalysts for efficient solar-to-hydrogen peroxide energy conversion from seawater

Solar-driven H2O2 photosynthesis from inexhaustible seawater is promising for alleviating increasingly-serious energy/environmental crises. Herein, a new metal-free photothermal-assisted photocatalyst containing strong π-stacked polyfuran D-A couples is synthesized by employing 5-hydroxymethylfurfural as precursor, which enables the highly-efficient H2O2 photosynthesis from seawater without any sacrificial agent. Its unique aromatic and quinoid furan alternating structure promotes the photogenerated charge transfer and the activation of oxygen molecules, thus remarkedly boosting H2O2 production rate. Furthermore, its localized photothermal and “electron bridge” effects can enhance the kinetic process of this reaction and accelerate the charge transfer, respectively, resulting in a high H2O2 yield of 1883.81 μmol g−1 h−1 with a high solar-to-chemical conversion efficiency of 0.48 % in seawater under simulated-sunlight irradiation. Impressively, it can achieve a high H2O2 concentration of 1867.81 μmol L−1 in natural seawater in one day under natural-sunlight irradiation, representing the first successful application of metal-free polyfuran photocatalysts for the photothermal-assisted H2O2 photosynthesis from natural seawater.

Challenges in photocatalysis using covalent organic frameworks

Photocatalysis is an attractive, energy-efficient technology for organic transformations, polymer synthesis, and degradation of environmental pollutants. There is a need for new photocatalysts stable in different media and that can be tailored for specific applications. Covalent organic frameworks (COF) are crystalline, nanoporous materials with π-conjugated backbone monomers, representing versatile platforms as heterogeneous, metal-free photocatalysts. The backbone structure can be tailored to achieve desired photocatalytic properties, side-chains can mediate adsorption, and the nanoporous structure provides large surface area for molecular adsorption. While these properties make COFs attractive as photocatalysts, several fundamental questions remain regarding mechanisms for different photocatalytic transformations, reactant transport into porous COF structures, and both structural and chemical stability in various environments. In this perspective, we provide a brief overview of COF photocatalysts and identify challenges that should be addressed in future research seeking to employ COFs as photocatalysts. We close with an outlook and perspective on future research directions in the area of COF photocatalysts.

Metal-Free C60-Doped Mesoporous Carbon Nitride Drives Red-Light Photocatalysis.

The pursuit of novel strategies for synthesizing high-performance nanostructures of graphitic carbon nitride (g-C3N4) has garnered increasing scholarly attention in the field of photocatalysis. Herein, we have successfully designed a metal-free photocatalyst by integrating mesoporous carbon nitride (mpg-C3N4) and C60 through a straightforward and innovative method, marking the first instance of such an achievement. Under red light, the C60/mpg-C3N4 composite exhibited a significantly accelerated rhodamine B (RhB) photodecomposition rate, surpassing bulk g-C3N4 by more than 25.8 times and outperforming pure mpg-C3N4 by 7.8 times. The synergistic effect of C60 and the mesoporous structure significantly enhanced the photocatalytic performance of g-C3N4 by adjusting its electronic structure, broadening the light absorption range, increasing the active sites, and reducing the recombination of photogenerated carriers. This work presents a promising avenue for harnessing a metal-free, stable, efficient photocatalyst driven by red light, with potential for enhancing solar energy utilization in environmental remediation.

Oxygen-enriched carbon quantum dots from coffee waste: Extremely active organic photocatalyst for sustainable solar-to-H2O2 conversion

Solar-driven artificial photosynthesis offers a promising avenue for hydrogen peroxide (H2O2) generation, an efficient and economical replacement for current methods. The efficiency and selectivity hurdles of the two-electron oxygen reduction reaction (ORR) in solar-to- H2O2 conversion are substantial barriers to large scale production. In this manuscript, a simple biomass-assisted synthesis was performed to produce oxygen-enriched carbon quantum dots (OE-CQDs) from spent coffee waste, acting as an efficient photocatalyst for solar-powered H2O2 production. OE-CQDs can stabilize and store light-generated electrons effectively, boosting charge separation and enhancing photocatalytic performance with longevity. The maximal photocatalytic H2O2 production was achieved viz the utilization of OE-CQDs with generation rate of 356.86 μmol g-1 h-1 by retaining 80% activity without any external sacrificial donors. The outstanding performance of synthesized OE-CQDs under light exposure at wavelength (λ) of 280 nm has been ensured by the quantum yield value of 9.4% upon H2O2 generation. The combinatorial benefits of OE-CQDs with their authentic crystalline structure and oxygen enrichment, is expected to be enhancing the ORR activity through accelerating charge transfer, and optimizing oxygen diffusion. Consequently, our eco-friendly method holds considerable promise for creating highly efficient, metal-free photocatalysts for artificial H2O2 production.

Shining bright: B@S-codoped graphitic carbon nitride nanorods illuminate enhanced catalytic C-N bond formation under visible-light

Graphitic carbon nitride as a photocatalyst seeking attention nowadays, due to its thermal stability, band structure, and chemical properties. Herein, we reported a boron sulfur co-doped graphitic carbon nitride (B@S-g-C3N4) photocatalyst synthesized by a one-pot thermal polycondensation mechanism. However, it was observed that due to co-doping in native carbon nitride structure the photocatalytic behavior and the band structure enhanced which was capable of fascinating the demand of organic transformations i.e. photocatalytic and charge transfer capability. The synthesized B@S-g-C3N4 photocatalyst was characterized by UV–vis DRS, FT-IR, XRD, SEM, EDX, HR-TEM, XPS and electrochemical properties. In addition, the synthesized B@S-g-C3N4 photocatalyst is a metal-free carbon nitride photocatalyst proven to be highly effective in performing organic transformations (conversion yield 98 %) like C-N bond formation under visible light source.

Significant augmentation of hydrogen and benzaldehyde production through mediator-free in-situ synthesis of CuNi/CN photocatalysts for benzyl alcohol splitting

Amidst growing concerns surrounding global warming and energy scarcity, there is an urgent demand for more efficient and environmentally friendly methods of hydrogen production. In response, we introduce a novel mediator-free in-situ approach for synthesizing CuNi/CN composite photocatalysts. This method entails the synthesis of copper and nickel complexes to fabricate bimetallic Cu and Ni nanoparticles on carbon nitride (CN). These catalysts are deployed for the photocatalytic dehydrogenation of benzyl alcohol, resulting in the generation of hydrogen and benzaldehyde. The CuNi bimetal-loaded CN structure provides ample active sites and demonstrates a low hydrogen reduction overpotential, thereby enhancing both charge separation and surface hydrogen reduction processes. In comparison to pure CN, the composite photocatalyst exhibits significantly improved photocatalytic activity. Notably, the composite 2 % Cu1Ni1/CN photocatalyst achieves a record-high hydrogen production rate of about 80 μmol g-1h−1, representing an impressive increase of approximately 533 times compared to pristine CN. Moreover, the catalyst offers cost-effectiveness, ease of preparation, and reusability, ensuring stable hydrogen production efficiency over multiple cycles. This precious metal-free composite photocatalyst not only facilitates the synthesis of valuable compounds but also promotes sustainable advancements in efficient hydrogen energy generation.

Novel Graphitic Carbon Nitride/Co-B-P Nanocomposites with Significantly Enhance Visible-Light Photocatalytic Hydrogen Production from Water Splitting

As a promising metal-free photocatalyst for hydrogen (H2) production through water splitting under visible-light irradiation, graphitic carbon nitride (g-C3N4) photocatalysts decorated with CoBP was prepared via simple ultra sonification. This paper highlights the structures of the photocatalysts, their stability, rate of hydrogen evolution and the mechanism of charge transfer within the photocatalysts. The prepared C3N4/CoBP nanocomposite photocatalysts were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and UV–visible (UV–vis) diffuse reflectance spectroscopy. After detailed analysis, the C3N4/CoBP nanocomposite photocatalysts showed excellent photocatalytic performance, which was due to the formation of the heterostructured hybrids of g-C3N4 and CoBP. The effects of C3N4/CoBP nanohybrids on H2 evolution were evaluated. The effects improved with increasing load of CoBP until the optimal level (5 wt% CoBP with visible-light irradiation at λ ≥420 nm). The maximum and remarkable photocatalytic H2 evolution rate of 51.68 μmol h−1 was achieved, which was 3.8 times that obtained from pure g-C3N4. Moreover, the C3N4/CoBP heterostructured nanohybrids demonstrated extremely high photostability and recyclability for H2 evolution after visible light illumination. The composite hybrid accelerated the separation and transfer of photogenerated charge carriers and subsequently suppressed charge recombination. Conclusively, this study offered an opportunity for the design and synthesis of highly stable and efficient C3N4/CoBP nanocomposite photocatalysts for energy conversion and utilisation.