Separation Of Photoinduced Carriers Research Articles

Enhanced Charge Transfer in Poly(Heptazine Imide) Synergistically Induced by Donor-Acceptor Motifs and Ohmic Junctions for Efficient Photocatalytic CO2 Reduction.

Poly(heptazine imide) (PHI) has received widely interest in the photocatalytic CO2 reduction due to its good crystallinity and complete in-plane structure. However, its poor photo-induced carrier separation and migration efficiency and insufficient active sites results in undesirable photocatalytic CO2 reduction performance. Herein, we designed and constructed a novel ohmic junction photocatalyst by integrating melamine edge-modified PHI (mel-PHI) with extended π-conjugated system with TiN (TiN/mel-PHI) for enhancing the photocatalytic CO2 reduction activity. Strikingly, the photocayalytic CO2 reduction yield of the optimal TiN/mel-PHI is 62.64 µmol·g-1·h-1, which is 5.6 and 2.8 times higher than PHI (11.26 µmol·g-1·h-1) and mel-PHI (22.32 µmol·g-1·h-1), respectively. The superior photocatalytic CO2 reduction activity is attributed not only to the formation of D-A structure by the introduction of melamine, which extends the π-conjugation system, alters the electronic structure of PHI, and accelerates the charge separation and migration, but also to the induced internal electric field by ohmic junction further enhances the charge separation and migration efficiency. Meanwhile, the synergistic effect of mel-PHI and TiN enriched the electron number of TiN, reducing the CO2 reduction potential. This work highlights the synergistic enhancement of charge transfer between D-A motifs and ohmic junctions, confirming their potential in optimizing photocatalysts.

Cu/S Co-anchoring junction boosted the photogenerated carrier separation efficiency in g-C3N5 for enhanced H2 evolution

C3N5 is emerging as an important visible light catalyst because of its narrow band gap, nontoxicity and thermal stability. Herein, sulfur-doped g-C3N5 (SCN) was prepared by copolymerization of thioacetamide (TAA) and 3-amino-1,2,4-triazole (3-AT). Then copper nanoparticles (Cu NPs) were anchored onto the SCN framework, resulting in the formation of Cu/SCN. It was found that the average H2 production rate of SCN and Cu/SCN was 0.76 and 1.34 mmol g−1 h−1, which was much higher than that of C3N5, respectively. Acting as a new active spots, sulfur doping effectively reduces the band gap of g-C3N5, and the formation of S-Cu bonds further creates an efficient electron transport pathway. As a result, Cu/SCN possesses a broader visible light absorption spectrum, stronger reduction capability, and greater efficiency in photo-induced carrier separation and transfer. Therefore, this work introduces a novel strategy for design of high efficiency photocatalytic H2 evolution carbon nitride through non-noble metal and sulfur anchoring junction.

Fe-N Co-Doped BiVO4 Photoanode with Record Photocurrent for Water Oxidation.

Bismuth vanadate (BVO) ranks among the most promising photoanodes for photoelectrochemical (PEC) water splitting. Nonetheless, slow charge separation and transport, besides the sluggish water oxidation kinetics, are key barriers to its photoefficiency. Here, we present a co-doping strategy that significantly improves the charge separation performance of BVO photoanodes. We found that, under standard one sun illumination, the Fe-N co-doped BVO photoanode (Fe-N-BVO) by N-coordinated Fe precursor reaches a record photocurrent density of 7.01 mA cm-2 at 1.23 V vs RHE after modified a surface co-catalyst (FeNiOOH), and exhibits an outstanding stability. By contrast, much lower photocurrent density is obtained for the N-doped, Fe-doped and Fe/N-doped BVO photoanode with separated N and Fe precursors. The detailed experimental characterizations show that the high activity of the Fe-N co-doped BVO photoanode is attributed to the enhanced photo-induced bulk charge separation, as well as the accelerated surface water oxidation kinetics. XPS, EXAFS and DFT calculations clearly show that, instead of formation of deep trapping state in the individually doped BVO, the co-doping of Fe-N into BVO generates Fe-based electronic states just below the bottom of conduction band and N-derived states just above the top of valence band. Such modulations in electronic structure enable the efficient trap of the electrons and holes to enhance the separation of photo-induced carriers, but hinder the charge recombination originated from the deep trapping sites.

Application of NiS modified WS2/TiO2 heterostructure in photocathodic protection

Stainless steel, as a popular corrosion resistant material, is still vulnerable to pitting corrosion in the marine environment. Therefore, in order to ensure the safety of stainless steel in the marine environment, it is necessary to implement corresponding protective measures. Titanium dioxide (TiO2), as an N-type semiconductor with excellent photoelectric properties, is widely used in the field of cathodic protection. However, as a photogenerated cathodic corrosion protection material, TiO2has the disadvantages of low conductivity and high carrier recombination rate. Therefore, WS2and NIS were introduced in this paper to modify it. TiO2/WS2/NiS (TWN) composites with Type-Ⅱ heterojunction structure were prepared by hydrothermal method and titration method. The results reveal TWN5 showed the best photoelectrochemical (PEC) performance, and the photocurrent density was 69% higher than that of a pure TiO2photoanode, and the photochemical and photocathodic protection performance was significantly better than that of pure TiO2. Under simulated ocean conditions, the self-corrosion potential of 304ss combined with TW5 and TWN5 photoanodes is reduced to -0.64 V and -0.7 V, respectively. The main reason is that the contact surfaces of WS2and TiO2formed a Type II heterostructure, which accelerates the separation and diffusion processes of photoinduced carriers. In addition, the plasmon resonance effect of NiS improves the ability to absorb visible light, and the metallic-like feature of NiS also promotes charge separation.

Synergistic effects of carbon coating and Bi-bridge in S-scheme C@CuO/Bi/Bi2MoO6 nanocomposites for enhanced photoreduction of Cr(VI)

The S-scheme mechanism in photocatalysis offers a promising approach to significantly enhance photoreductive activity. Here, using Bi dots as electronic media, and by changing the amount of added C@CuO on the surface of flower-shaped Bi2MoO6, a diverse range of CBM-x heterojunctions, were synthesized using a multi-step approach that incorporated solvothermal preparation and calcination methods. CBM-10 exhibited excellent photocatalytic activity: 96.9 % of Cr(VI) removal in 30 min, which was 38.0-fold better than CuO, 4.2-fold higher than pristine Bi2MoO6. Furthermore, even after five cycles of use, CBM-10 showed outstanding stability. Experiments to capture the active species revealed that electrons play a crucial role in the photocatalytic reduction of Cr(VI). In these heterojunctions, carbon doping leads to the formation of coatings on the semiconductor materials to promote the migration and separation of photogenerated carriers. The presence of carbon coating is beneficial to improve the stability of CBM-10. Bi dots grown on Bi2MoO6 nanosheets can act as electron transport channels in C@CuO/Bi/Bi2MoO6, accelerate photoinduced carrier separation. The internal electric field, and the existence of “S-scheme” charge transfer mechanism was verified by the combination of atomic force microscope and synchronous illumination X-ray photoelectron spectroscopy. This process significantly mitigates the recombination of photo-induced carriers, enhancing the overall photoreduction efficacy. This study presents a novel method for developing S-scheme heterojunction to enhance the effectiveness of Cr(VI) decontamination, paves a promising route to heavy metal removal by mild photo-reductive system, and provides new insights into the design of photocatalysts with enhanced redox capabilities.

Enhanced piezo-photocatalytic activity of ZnS/Fe2O3: Benefit from type I junction and weak water flow-induced piezoelectric polarization

Photocatalysis is considered to be a sustainable and less polluting environmental purification technology, however, the limited photogenerated charge separation efficiency and light absorption hinder its large-scale application. Encouragingly, piezocatalysis is proposed as an emerging and appealing strategy to drive the migration and separation of photoinduced carriers. Nevertheless, the source of piezocatalysis is usually derived from high energy-consuming ultrasonic vibration. Herein, we realize superior piezo-photocatalytic chlortetracycline hydrochloride degradation performance stimulated by low-frequency water flow-driven piezoelectric polarization of I-type ZnS/Fe2O3 junction. The integration of Fe2O3 is beneficial to extend the light absorption from ultraviolet region to visible range and boost the charge separation efficiency of ZnS/Fe2O3. Meanwhile, the piezoelectric polarization triggered by weak water flow further promotes the directional separation of photogenerated carriers. With all these merits, the optimized ZnS/Fe2O3 shows a piezo-photocatalytic chlortetracycline hydrochloride (CTC) degradation rate of 73.2 % within 20 min, which is 2.8 and 2.1 times that of Fe2O3 and ZnS, respectively, and 17.4-fold and 1.1-fold that of single stirring and light, respectively. This work provides a feasible guidance for designing efficient piezo-photocatalysts for in-situ purification of wastewater in natural environmental with effective visible light responsiveness and sensitivity to weak mechanical stress.

Two-dimensional hierarchically porous C3N4 for photocatalysis: perspective and challenges

Owing to its unique structure, porosity and photoresponse properties, two-dimensional hierarchically porous (2D-HP) C3N4 has attracted wide attention in environmental remediation and sustainable energy evolution fields. Up to today, 2D-HP C3N4 has been developed as an efficient photocatalyst for various environmental/energy photocatalytic applications. Its advantages in promoting light harvesting, reactant diffusion and transportation, surface molecule activation and photoinduced carrier separation have been verified. In this perspective, we highlighted the advantages of 2D-HP C3N4 in various photocatalytic reactions such as water splitting and H2O2 production. The relevant mechanism was simultaneously discussed. Moreover, the prospects and obstacles for the industrial utilization of 2D-HP C3N4-based photocatalysts are outlined and summarized. Finally, we envision available approaches for the deployment of 2D-HP C3N4-based materials to promote its practical application.

Confining CsPbI3 perovskite in metal organic framework (MOF-545) as stable composite photocatalyst for efficient oxygen-tolerant NIR light-driven atom transfer radical polymerization

Zirconium-porphyrin metal-organic framework (MOF-545) encapsulated all inorganic iodide perovskite (CsPbI3) composite (CsPbI3@MOF-545) is used as highly efficient photocatalyst to catalyze NIR light induced atom transfer radical polymerization (ATRP). The combination of CsPbI3 and MOF-545 leads to a synergistic effect with enhanced photoinduced carrier separation and light absorption performance in the composite photocatalyst. The constructed CsPbI3@MOF-545(10 %) can efficiently catalyze the conversion more than 90 % of various monomers under 810 nm NIR light irradiation. Strong oxygen-resistance has been confirmed in the CsPbI3@MOF-545(10 %) catalyzed photo-ATRP system. In a large-volume photo-ATRP system (100 mL), the polymerization of methyl methacrylate (MMA) achieved a conversion over 90 % in 10 h using NIR light in air. The success of chain extension and block polymerization indicates good end-chain fidelity for the synthesized polymers. The composite photocatalyst still displays high photocatalytic activity for the synthesis of polymers with controllable dispersity after seven photopolymerization cycles, demonstrating its promising potential for practical applications.

Modulating Eco-friendly Colloidal AgGaS2 Quantum Dots for Highly Efficient Photodetection and Image Sensing via Direct Growth of Ternary AgInS2 Shell.

Tailoring the optoelectronic characteristics of colloidal quantum dots (QDs) by constructing a core/shell structure offers the potential to achieve high-performing solution-processed photoelectric conversion and information processing applications. In this work, the direct growth of wurtzite ternary AgInS2 (AIS) shell on eco-friendly AgGaS2 (AGS) core QDs is realized, giving rise to broadened visible light absorption, prolonged exciton lifetime and enhanced photoluminescence quantum yield (PLQY). Ultrafast transient absorption spectroscopy demonstrats that the photoinduced carrier separation and transfer kinetics of AGS QDs are significantly optimized following the AIS shell coating. As-synthesized environmentally benign AGS/AIS core/shell QDs are employed to fabricate photodetectors (PDs), showing a remarkable responsivity of 38.4 AW-1 and a detectivity of 2.4×1012 Jones under visible light illumination (405 nm). Moreover, the fabricated QDs-PDs exhibit superior image-sensing capability to record complex patterns with high resolution (160×160 pixels) under visible light illumination at 405 and 532 nm. The findings indicate that the direct growth of multinary narrow-band shell materials on eco-friendly QDs holds great promise to implement future "green", cost-effective and high-performance optoelectronic sensing/imaging systems.

Enhanced Photothermal-Assisted Hydrogen Production via a Porous Carbon@MoS2/ZnIn2S4 Type II-S-Scheme Tandem Heterostructure.

MoS2/ZnIn2S4 flower-like heterostructures into porous carbon (PC@MoS2/ZIS) are embedded. This ternary heterostructure demonstrates enhanced light absorption across a broad spectral range from 200 to 2500nm. It features both Type-II and S-scheme dual heterojunction interfaces, which facilitate the generation, separation, and transfer of photoinduced carriers. The PC enveloped by MoS2/ZIS composite microspheres serves as a photothermal source, providing additional energy to the carriers. This process accelerates charge separation and migration, enhancing photothermal-assisted photocatalytic H2 evolution. The optimal H2 evolution rate for PC@MoS2/ZIS reaches an impressive 18.79mmolg-1h-1, with an apparent quantum efficiency of 14.1% at 400nm. This work presents a promising approach for effectively integrating multicomponent heterostructures with photothermal effects, offering innovative strategies for efficient solar energy utilization and conversion.

Ultrathin 2D/2D MoS2/Bi2WO6 S-scheme heterojunction for boosting photocatalytic degradation of ciprofloxacin

A series of 2D/2D MoS2/Bi2WO6 S-scheme heterojunctions consisting of ultrathin MoS2 nanosheets (MS, 1.6 nm) and ultrathin Bi2WO6 nanosheets (BWO, 1.5 nm) were developed for photocatalytic degradation of ciprofloxacin. The samples with 5 % mass ratio of MS (5 %MS/BWO) exhibits the almost complete degradation of ciprofloxacin (≈100 %) under visible light. It is evidenced that the formation of S-scheme heterojunction with close interfacial interaction facilitates the photoinduced carrier separation and the generation of surface acid sites. The activation of ciprofloxacin molecules is realized through the coordinately interaction of C-N and C=O with the surface W sites. Moreover, the OVs in BWO side is a convenient pathway for activated of O2, embodying in the generation of •O2− and •OH under visible light over photocatalyst. Such an association of charge transfer mechanism with coordination activation shows the enhanced photocatalytic performance toward ciprofloxacin. This work provides a motivation which designs an S-scheme heterojunction photocatalyst with the ability to activate the specific group in molecules to comprehend the degradation of antibiotics.

Exploring Geometric Chirality in Nanocrystals for Boosting Solar-to-Hydrogen Conversion.

Advancing catalyst design is pivotal for the enhancement of photocatalytic processes in renewable energy conversion. The incorporation of structural chirality into conventional inorganic solar hydrogen nanocatalysts promises a significant transformation in catalysis, a feature absent in this field. Here we unveil the unexplored potential of geometric chirality by creating a chiral composite that integrates geometric chiral Au nanoparticles (NPs) with two-dimensional C3N4 nanosheets, significantly boosting photocatalytic H2 evolution beyond the achiral counterparts. The superior performance is driven by the geometric chirality of Au NPs, which facilitates efficient charge carrier separation through the favorable C3N4-chiral Au NP interface and chiral induced spin polarization, and exploits high-activity facets within the concave surfaces of chiral Au NPs. The resulting synergistic effect leads to a remarkable increase in photocatalytic H2 evolution, with an apparent quantum yield of 44.64 % at 400 nm. Furthermore, we explore the selective polarized photo-induced carrier separation behavior, revealing a distinct chiral-dependent photocatalytic HER performance. Our work advances the design and utilization of chiral inorganic nanostructures for superior performance in energy conversion processes.

Chemically bonded to construct S-scheme CNQDs/Bi2WO6 heterostructure: The Bi-N bonds as interfacial electronic channel boosting the efficient photocatalytic CO2 reduction under simulated sunlight

Photoinduced carrier separation efficiency plays a crucial role in determining the photocatalytic activity of photocatalysts, but it remains a challenge to accurately and efficiently control charge separation. Hence, we successfully prepared S-scheme CNQDs/Bi2WO6 heterostructure via a simple hydrothermal method. The theoretical calculations demonstrate that Bi-N bonds at the interface between CNQDs and Bi2WO6 serve as an electron transfer channel to facilitate charge transfer at the atomic level, which plays a vital role in driving the photoreduction of CO2 to CO. Interestingly, S-scheme heterostructure not only remains strong reducing ability of CNQDs, but also significantly reduces the energy barrier of *CO2 *COOH and release the product CO easily. The CO yield of the CNQDs/Bi2WO6 sample (26.24 µmol/g) was 11 times higher than that of the pure Bi2WO6 (2.43 µmol/g) without any sacrificial agents under 300 W xenon lamp. This work highlights the critical role of chemical bonding interfaces in the design of efficient S-scheme heterostructure photocatalysts.

Photocatalytic Reforming of Ethanol in the Liquid Phase Using a Ternary Composite of Rh/TiO2/g-C3N4 as a Catalyst.

Photocatalytic reforming of ethanol provides an effective way to produce hydrogen energy using natural and nontoxic ethanol as raw material. Developing highly efficient catalysts is central to this field. Although traditional semiconductor/metal heterostructures (e.g., Rh/TiO2) can result in relatively high catalyst performance by promoting the separation of photoinduced hot carriers, it will still be highly promising to further improve the catalytic performance via a cost-effective and convenient method. In this study, we developed a highly efficient photocatalyst for ethanol reformation by preparing a ternary composite structure of Rh/TiO2/g-C3N4. Hydrogen is the main product, and the reaction rate could reach up to 27.5 mmol g-1 h-1, which is ∼1.41-fold higher than that of Rh/TiO2. The catalytic performance here is highly dependent on the wavelength of the light illumination. Moreover, the photocatalytic reforming of ethanol and production of hydrogen were also dependent on the Rh loading and g-C3N4:TiO2 ratio in Rh/TiO2/g-C3N4 composites as well as the ethanol content in the reaction system. The mechanism of the enhanced hydrogen production in Rh/TiO2/g-C3N4 is determined as the improvement in the separation of photoinduced hot carriers. This work provides an effective photocatalyst for ethanol reforming, largely expanding its application in the field of renewable energy and interface science.

Supersaturation- and external force-engineered high-quality 2D CsCu2I3 single-crystalline film for heterogeneous integration in photodetectors

Heterogeneous integration of various crystalline materials in electronic and optoelectronic devices have fueled the development of two-dimensional (2D) perovskite single-crystalline (SC) film. However, it is still challenging to synthesize 2D CsCu2I3 SC film due to the uncontrolled nuclei/growth. In the work, the bottleneck for the synthesis of 2D CsCu2I3 SC film can be well tackled by the solution supersaturation and external pressure for the first time, meanwhile, the morphological transformation of CsCu2I3 from dendritic crystal to 2D film are firstly achieved through controlling nucleation driving force. The heterogeneous integration of 2D CsCu2I3 SCs film on various substrates was demonstrated, a self-powered GaN-CsCu2I3 SC film photodetector exhibits high rectification ratio of 1250 (±1 V) with improved responsivity of 460 mA W−1 and EQE of 163 %, which outperforms most reported 2D lead-free halide perovskite film photodetectors. Furthermore, theoretical computational calculation was employed to investigate their crystal structure and electronic distribution, evidencing that 2D CsCu2I3 SC film could facilitate the separation of photo-induced carriers. The study not only shows an in-depth mechanism for perovskite growth, but also advances the development of 2D copper-based perovskite film and hetero-integration, laying the groundwork for future commercial optoelectronics.

Efficient ofloxacin degradation via peroxymonosulfate activation using an S-scheme MoS2/Co3O4 heterojunction composite under visible light: Performance and mechanistic insights

Sulfate-radical-mediated photocatalysis technology peroxymonosulfate (PMS) activation via visible light irradiation shows great promise for water treatment applications. However, its effectiveness largely depends on the bifunctional performance of photocatalysis and PMS activation provided by the catalysts. In this study, we successfully synthesized a novel S-scheme MoS2/Co3O4 (MC) heterojunction composite by a hydrothermal method and employed it for the first time to activate PMS for ofloxacin (OFX) degradation under visible light irradiation. The MC-5/PMS/Vis system achieved an impressive 85.11% OFX degradation efficiency within 1 min and complete OFX removal within 15 min under optimal conditions, with an apparent first-order kinetics rate constant of 0.429 min−1. Reactive species trapping experiments and electron spin resonance analysis identified 1O2, h+, and •O2− as the primary active species responsible for OFX degradation. Photoelectrochemical analyses and density functional theory calculations indicated the formation of a built-in electric field between MoS2 and Co3O4, which enhanced the separation and migration of photoinduced carriers. Additionally, the Co–Mo interaction further increased the yield of dominant reactive species, thereby boosting photocatalytic activity. This work underscores the potential of visible-light-assisted PMS-mediated photocatalysis using Co3O4-based catalysts for effective pollutant control.

Construction of S-scheme heterojunction via Cu2ZnSnS4 coupled with g-C3N4 for enhancing HER performance

It is shown that replacing non-noble metals with noble metals in photocatalytic water splitting is pivotal for increased and sustained hydrogen production. However, the challenge persists in designing and developing a cost-effective, highly active catalyst with effective carrier separation and providing sufficient H+ reduction sites to enhance photocatalytic H2 evolution efficiency. Herein, a series of S-scheme Cu2ZnSnS4/g-C3N4 (CZTS/CN) heterojunction composites were prepared via the hydrothermal method, followed by comprehensive characterizations for in-depth investigation. The TEM image exhibits a clear interface, showing the heterojunction formation between CZTS and CN nanosheets. The results show that incorporating CZTS cocatalyst significantly improves CN photocatalytic hydrogen evolution reaction (HER) and its performance is notably influenced by CZTS to CN mass ratio. Among CZTS/CN heterojunction composites, the 5% CZTS/CN heterojunction composite exhibited a significantly improved HER of 243.64 μmol g−1h−1, which is 29.4 and 7.08 folds superior as compared to CN (8.29 μmol g−1h−1) and CZTS (34.42 μmol g−1h−1), respectively. The mechanism study revealed that the excellent superior H2 evolution performance resulted from the established internal electric field (IEF) in p-n heterojunction, which expedites the efficient separation and migration of photoinduced carriers coupled with the distinctive flower-like configuration of CZTS offering a substantial surface area and enough active reduction sites for photocatalysis process. This work presents a rational design and an inexpensive and efficient heterojunction photocatalysis system suitable for diverse applications.

Ultrafast carrier dynamics triggered by Ga-S bond in GaZnON/CdS heterojunction for efficient photocatalytic hydrogen evolution

Constructing heterojunction has been regarded as a valid strategy of photocatalysts to promote the catalytic process. However, beyond the possible synergistic advantage from the component catalysts, the understanding of the interface effect on the photocatalytic process within heterojunction remains challenging. Herein, we prepare a novel GaZnON/CdS heterojunction photocatalyst via a robust electrostatic assembly method. The sulfur atoms in CdS are found to occupy the nitrogen vacancy over the GaZnON surface to form interfacial Ga-S bonds, which is proved as electron-transfer channel between CdS and GaZnON to realize efficient photo-induced carrier separation. The dynamic study quantificationally reveals interfacial electron transfer with a fast transfer rate of 143.8 ns−1. Thereby, the optimal composite photocatalyst reached an impressive hydrogen evolution rate of 14.76 mmol g-1h−1, as well as an impressive AQY of 36.1 % (450 nm). This work expounds the ultrafast carrier dynamics underlying interface bonds within heterojunction for weakened photo-induced carrier recombination.

Electrode materials and structures in UV photodetectors

Electrodes can be recognized as the bridges between photodetectors (PDs) and outer measurement circuits. The interfacial electric properties between electrodes and sensitive materials would dominate the separation and collection of photo-induced charge carrier, which are recognized as one of the critical factors influencing the photo-detecting performance. In this paper, the electrode materials used in UV PDs are summarized and categorized according to their components. Then, the effects of electrode configurations (such as the contact types, band structure, and electrode structure) on the photoelectric performances of UV PDs are discussed. Varied kinds of specific electrodes such as transparent electrodes, flexible electrodes, and bio-originated electrodes are described. Finally, the perspective of electrodes in UV PDs is presented, which provides guidance for their future development.

Insights from DFT and mechanistic analysis of surface-precision carbon self-doped porous g-C3N4 for enhanced visible light-driven hydrogen evolution

Substituting carbon for nitrogen in g-C3N4 enhances π-electrons activity and photocatalytic performance, despite the challenges posed by the higher electronegativity of nitrogen. We successfully achieved the substitution of C atoms for N atoms via the copolymerization of melamine and cytosine utilizing the Schiff base reaction, altering the g-C3N4 band structure from 2.74 to 2.49 eV and enhancing photoinduced electron reduction due to the introduction of −N-C = C- unit into the g-C3N4 network. The C-incorporated g-C3N4 extended the light-response range to 673 nm and improved the electron cloud density around the self-doping sites, significantly reducing the ΔGH* as indicated the DFT results, implying the efficient separation and migration of photoinduced carriers in g-C3N4. As anticipated, the photocatalytic hydrogen evolution (PHE) rate of the optimized C self-doped g-C3N4 was five and seven times higher than that of the pristine g-C3N4 under the full spectrum and the visible light (λ ≥ 400 nm), respectively. Moreover, g-C3N4-n also display superior activity (6.73, 4.48, 3.42, and 0.76 %) under the different wavelengths (λ = 420, 450, 480 nm, and 540 nm respectively). This report reveals a subtle atom-tailoring scheme to control carbon self-doping sites within the g-C3N4 framework, modulating its inherent electronic properties and photoactivity.