Pt@Ni2P/C3N4 for charge acceleration to promote hydrogen evolution from ammonia-borane

Incorporating g-C₃N₄ with transition metal phosphides is emerging as a low-cost and robust co-catalyst for hydrogen evolution. The ammonia borane hydrolysis is an efficient method to release H₂ at ambient conditions in the presence of a catalyst. An efficient and cheap catalyst is needed for practical application to achieve this benchmark. For this purpose, a catalyst Ni₂P/C₃N₄ is synthesized by hydrothermal method and low-temperature phosphidation. The optimization reveals that the Ni₂P/C₃N₄ with 6.5% Ni contents shows the best performance for H₂ release. Furthermore, 2% Pt nanoparticles loading over Ni₂P/C₃N₄ boosts the charge transfer and improves activity 5.7-fold compared to Ni₂P/C₃N₄, and the Pt-loaded catalyst is depicted as Pt@Ni₂P/C₃N₄. The reaction kinetics reveals that the hydrogen evolution rate accelerates by increasing the amount of Pt@Ni₂P/C₃N₄ and AB concentration, and the loading of Pt nanoparticles loaded over Ni₂P/C₃N₄ reduces the activation energy significantly. Moreover, the ionic interaction between Pt and Ni₂P/C₃N₄ generates Ptᵟ⁺ and (Ni₂P/C₃N₄)ᵟ⁻ active sites which facilitates B–H cleavage and O–H bonds of ammonia borane and water, respectively. Incorporating transition metals phosphide and noble metals supported over g-C₃N₄ paves the pathway toward the efficient H₂ evolution from ammonia borane, bringing cost-effective modifications to synthesize constructive catalysts.     

Platinum nanoparticles decorated on graphitic carbon nitride-ZIF-67 composite support: An electrocatalyst for the oxidation of butanol in fuel cell applications

In the present study, we report an eco-friendly and simple route to design and synthesize novel nanocomposite catalyst based on platinum nanoparticles anchored on binary support of graphitic carbon nitride (g-C₃N₄) and cobalt-metal-organic framework (ZIF-67). For this purpose, ZIF-67 was prepared by precipitation method and g-C₃N₄ was prepared through thermal polymerization method. Later, ZIF-67 and g-C₃N₄ were hybridized through sonication to get homogeneous g–C₃N₄–ZIF-67 nanocomposite support material. Platinum nanoparticles (PtNPs) were uniformly deposited on g–C₃N₄–ZIF-67 by an electrochemical method. The as-developed nanocatalyst was characterized by morphological, structural and electrochemical techniques. The electrocatalytic activity of PtNPs@g–C₃N₄–ZIF-67 nanocatalyst towards butanol oxidation was evaluated via CV, CA, LSV and EIS in an alkaline medium. Results revealed that the proposed catalyst showed greatly enhanced electrooxidation of butanol in terms of high magnificent current density, lower oxidation potential, excellent long-term stability, large surface area, low charge transfer resistance and less toxic ability. Enhanced catalytic performance of the proposed catalyst could be ascribed to the synergistic effect of g–C₃N₄–ZIF-67 nanocomposite and PtNPs. The PtNPs@g–C₃N₄–ZIF-67 catalyst holds promising potential applications to be used as an anodic electrocatalyst for the development of high-performance alkaline fuel cells.     

Greatly enhanced photocatalytic hydrogen production on CdS/(Pt/g-C3N4) via dual functions of Pt on semiconductors interface

CdS and g-C₃N₄ are famous semiconductors in photocatalytic hydrogen evolution, however, their low efficiencies limit their further application. Here, a highly efficient ternary catalyst CdS/(Pt/g-C₃N₄) was reported and its photocatalytic hydrogen production activity reached up to 1465.9 μmol/h/g, which is 5.3 times of Pt/CdS and 4.0 times of Pt/g-C₃N₄, respectively. TEM and HRTEM images demonstrate the Pt nanoparticles exists on the interface of between CdS and g-C₃N₄ acting as a cocatalyst for hydrogen evolution. SPV spectra and electrochemical tests demonstrate that Pt as bridge between CdS and g-C₃N₄ also accelerates the electrons transforming which benefits for the inhibition of the recombination of photoexcited electrons and holes. This study demonstrated the dual roles of interface Pt and provides a new method to design a highly efficient photocatalyst.     

Platinum deposition onto g-C3N4 with using of labile nitratocomplex for generation of the highly active hydrogen evolution photocatalysts

The chemisorption of the labile dimeric platinum nitratocomplex [Pt₂(μ-OH)₂(NO₃)₈]^2- onto graphene oxide doped graphitic C₃N₄ (g–C₃N₄–GO) was performed for the first time to prepare PtO_x/g–C₃N₄–GO composites with ionic platinum species (Pt(II)) bonded with N-donor groups of the g-C₃N₄. The thermal treatment of the obtained composites in the hydrogen atmosphere results in a gradual reduction of Pt(II) species with the formation of Pt/g–C₃N₄–GO photocatalysts. The Pt/g–C₃N₄–GO catalysts paired with TEOA sacrificing agent in an aqueous solution were tested in a photoinduced hydrogen evolution reaction under visible light (λ = 425 nm). The photocatalytic activity of prepared materials strongly influenced by the temperature of the reduction stage so that the maximal rate of H₂ evolution was revealed for the catalyst (0.5 wt% of Pt) reduced at 400 °C with a quantum efficiency of 3.0% and rate of HER of 5.1 mmol h^?1 per 1 g of photocatalysts. The photocatalytic activity of this sample was much higher than the activity of 0.5% Pt/g–C₃N₄–GO photocatalysts prepared by conventional photoreduction of H₂PtCl₆ or reduction of this precursor with NaBH₄. The Pt/g–C₃N₄–GO photocatalyst with Pt concentration of 0.1 wt% was prepared using the described protocol and shown specific activity of about 1.4 mol h^?1 per 1 g of Pt outperforming analogous material reported to date.     

Synthesis of Au-NiOx/ultrathin graphitic C3N4 nanocomposite for electrochemical non-platinum oxidation of methanol

The Au-NiO_x/g-C₃N₄ (graphitic C₃N₄) nanocomposite is synthesized and utilized as catalyst for the electrochemical oxidation of methanol in the alkaline electrolyte. Au and Ni nanoparticles are uniformly dispersed on ultrathin g-C₃N₄ nanosheets by in-situ synthesis with nickel nitrate and chloroauric acid as Ni and Au resource respectively. The structure, morphology and component of the prepared nanocomposites are characterized by different techniques like transmission electron microscopy, X-ray diffraction, elemental mapping image and X-ray photoelectron spectroscopy. The results prove that the nanoparticles are well-distributed and embedded in g-C₃N₄ nanosheets. The electrochemical performance of different nanocomposite for methanol oxidation reaction (MOR) is tested under alkaline conditions via electrochemical technologies. Compared to the pure g-C₃N₄ and Au/g-C₃N₄, the NiO_x/g-C₃N₄ exhibits electrochemical catalytic effect toward methanol electro-oxidation with the existence of Ni. This electrochemical catalytic performance is enhanced significantly for the Au-NiO_x/g-C₃N₄, whose oxidation peak current density is 2.32 times higher than NiO_x/g-C₃N₄. The slope value drew from the Tafel plots shows that the Au-NiO_x/g-C₃N₄ owns the lowest Tafel slope (67.00 mV/dec). After the 7200 s stability test, the Au-NiO_x/g-C₃N₄ catalyst can still maintain a high current density. Long-term stability and good anti-poisoning ability promise Au-NiO_x/g-C₃N₄ a competitive non-Pt catalyst for the methanol oxidation.     

Fabrication of alveolate g-C3N4 with nitrogen vacancies via cobalt introduction for efficient photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution is a promising method for converting solar energy into chemical energy. Herein, on the basis of graphitic carbon nitride (g-C₃N₄) material with alveolate structure prepared via the hard template method, transition-metal cobalt oxide nanoparticles were reasonably introduced, and a highly efficient cobalt oxide composite alveolate g-C₃N₄ (ACN) photocatalyst was successfully prepared. A series of test methods were used to characterize the structural properties of the prepared samples systematically, and the photocatalytic activity of the catalysts in photocatalytic hydrogen evolution was explored. The composite materials have excellent photocatalytic performance mainly because the synergistic effect of the alveolate structure of ACN provides multiple scattering effects; nitrogen vacancies serves as the centers of photogenerated carrier separation; and cobalt oxides accelerates electron transfer. This study provides a new idea for the design of g–C₃N₄–based photocatalysts with wide light responses and simple structures.     

Synthesis of solar-light responsive Pt/g-C3N4/SrTiO3 composite for improved hydrogen production: Investigation of Pt/g-C3N4/SrTiO3 synthetic sequences

Solar-light responsive platinum/graphite-like carbon nitride/strontium titanate (Pt/g-C₃N₄/SrTiO₃) with excellent charge separation was synthesized via thermal treatment process. A photocatalytic hydrogen production rate of 552 μmol/h/g was achieved under simulated sunlight irradiation for the Pt/(g-C₃N₄/SrTiO₃) catalyst with 5 v/v% triethanolamine (TEOA) as a sacrificial agent. The hydrogen production rate of Pt/g-C₃N₄/SrTiO₃ prepared via different synthetic sequences decreased in the following order: Pt/(g-C₃N₄/SrTiO₃) > (Pt/g-C₃N₄)/SrTiO₃ > g-C₃N₄/(Pt/SrTiO₃). The mechanisms of electron transfer in the different synthetic sequences of Pt/g-C₃N₄/SrTiO₃ were investigated. The electron transfer pathway of Pt/(g-C₃N₄/SrTiO₃) was as follows: (1) g-C₃N₄→SrTiO₃→Pt, (2) g-C₃N₄→Pt, (3) SrTiO₃→Pt, and (4) g-C₃N₄→SrTiO₃, leading to optimal charge separation and H⁺ ion reduction.     

Polyaniline decorated MoO3 nanorods: Synthesis,characterization and promoting effect to Pt electrocatalyst

The promoting effect of metal oxides to Pt catalysts toward methanol oxidation reaction (MOR) has attracted widespread attention in recent years. In this communication, we report the promoting effect of MoO₃ to Pt catalyst by rationally designing and tuning the nanostructure of the catalysts. MoO₃ nanorods are firstly synthesized through hydrothermal method and used as the substrate for the deposition of polyaniline (PANI) layer. The PANI-MoO₃ composite nanostructures are then used as the support for Pt catalyst. Depending on the preparation method of Pt nanoparticles, the nanostructure can be PANI nanotube supported Pt (Pt/PANI) through etching MoO₃ nanorods with NaBH₄ and PANI-MoO₃ composite nanorods supported Pt (Pt/PANI-MoO₃). The catalytic properties of the two catalysts toward MOR are investigated. Results show that the current of methanol oxidation on Pt/PANI-MoO₃ catalyst is comparable to that on Pt/PANI, while the peak potential of MOR on the former is lowered by 180 mV as compared with the latter, suggesting a much higher catalytic activity of Pt/PANI-MoO₃. The presence of MoO₃ may be responsible for the improvement of the catalytic properties through the co-synergistic effects of PANI and MoO₃.     

Hydrogen evolution from hydrolysis of ammonia borane catalyzed by Rh/g-C3N4 under mild conditions

Developing effective catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is of great significance considering the useful applications of hydrogen. Herein, graphitic carbon nitride (g-C₃N₄) prepared through the simply pyrolysis of urea was employed as a support for Rh nanoparticles (NPs) stabilization. The in-situ generated Rh NPs supported on g-C₃N₄ with an average size of 3.1 nm were investigated as catalysts for hydrogen generation from the hydrolysis of AB under mild conditions. The Rh/g-C₃N₄ catalyst exhibits a high turnover frequency of 969 mol H₂· (min·mol_Rh)^?1 and a low activation energy of 24.2 kJ/mol. The results of the kinetic studies show that the catalytic hydrolysis of AB over the Rh/g-C₃N₄ catalyst is a zero-order reaction with the AB concentration and a first-order reaction with the Rh concentration. This work demonstrates that g-C₃N₄ is a useful support to design and synthesis of effective Rh-based catalyst for hydrogen-based applications.     

Three dimensional nitrogen,phosphorus and sulfur doped porous graphene as efficient bifunctional electrocatalysts for direct methanol fuel cell

The development of efficient and durable bifunctional catalysts for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) is desirable but remains a great challenge. Herein, a series of new three-dimensional (3D) nitrogen, phosphorus and sulfur doped porous graphene (NPS G) were fabricated by facile and cost-effective strategy, as efficient bifunctional electrocatalysts for direct methanol fuel cell. To obtain superior ORR and MOR bifunctional catalytic activities, we optimized the doping amount of nitrogen, phosphorus and sulfur in catalysts. The resulting metal-free NPS G₂ catalyst had a long-term stability, desirable four electron pathway and excellent methanol poisoning tolerance. Moreover, NPS G₂ exhibited higher onset potential compared to other metal-free NPS G, and close to commerical Pt/C catalyst current density under the same conditions. In addition, a series of NPS G used as good supports for Pt nanoparticles. Pt/NPS G₂ catalyst displayed remarkable electrochemical performance, better cyclic stability and tolerance in methanol electrooxidation reaction.     

Investigation of Photo(electro)catalytic water splitting to evolve H2 on Pt-g-C3N4 nanosheets

g-C₃N₄ has shown great potentials in photocatalytic water splitting to produce hydrogen. Herein, we successfully synthesized g-C₃N₄ nanosheets via exfoliating bulk g-C₃N₄. And different metal nanoparticles were photo-deposited onto the surface of g-C₃N₄ nanosheets. The photocatalytic H₂ production activity of g-C₃N₄ nanosheets increased from 0 to 11.2 μmol/h/g_cat. The Pt loaded g-C₃N₄ nanosheets manifested the highest H₂ production activity with a rate of 589.4 μmol/h/g_cat. In addition, the hydrogen evolution rate was further enhanced with addition of external bias to fabricate a photoelectrocatalytic (PEC) system. And the maximum hydrogen production rate (23.1 mmol/h/m²) was obtained at a voltage of 0.6 V (vs. Ag/AgCl). The enhancement in H₂ production may be due to the following reasons: (1) Two-dimensional atomic flakes is beneficial to increase the specific surface area of g-C₃N₄, enhance the mobility of carriers, and improve the energy band structure, (2) Pt nanoparticles play an important role in g-C₃N₄ electron transport, (3) the g-C₃N₄ nanosheets loaded with Pt nanoparticles exhibited significant enhancement in photoelectrocatalytic performance, which may be attributed to its enhanced electronic conductivity and photoelectrochemical surface area, (4) Pt inhibited the recombination of photogenerated carriers and significantly improved the photocatalytic performance. The enhancement mechanism was deeply discussed and explained in this work.     

Enhanced formic acid dehydrogenation by the synergistic alloying effect of PdCo catalysts supported on graphitic carbon nitride

The catalytic ability of graphitic carbon nitride (g-C₃N₄)-supported composition-controlled PdCo catalysts towards H₂ generation from the formic acid dehydrogenation reaction was assessed in this study and a noticeable composition dependence was evidenced. It was seen that the alloying effect combined with the nitrogen functionalities present on g-C₃N₄ assisted the formation of small and well-distributed nanoparticles. This fact, combined with the electronic promotion of Pd species via charge transfer from Co and basic features of the support, resulted in enhanced catalytic activities compared to that displayed by the counterpart Pd/g-C₃N₄, reaching a TOF value of 1193 h⁻¹ for the most active catalyst among investigated (PdCo/g-C₃N₄ (1/0.7)). Furthermore, the present catalytic system showed high selectivity towards formic acid dehydrogenation, suppressing the generation of undesired CO via formic acid dehydration, which makes it a suitable candidate for practical application in fuel cells.     

Performance of g-C3N4 nanoparticles by EDTA modification and protonation for hydrogen release from sodium borohydride methanolysis

Here, for the first time, a metal-free catalyst was synthesized by ethylenediamine tetra-acetic acid (EDTA) modification of the carbon nitride (g-C₃N₄) sample and protonation of the obtained sample. The catalyst was used for the production of H₂ from the methanolysis of sodium borohydride (NaBH₄). The EDTA modification and protonation of the g-C₃N₄ sample was confirmed by XRD, FTIR, SEM-EDX, and TEM analyses. During the hydrogen generation, NaBH₄ concentration effect, catalyst amount effect, temperature effect and catalyst reusability were investigated. The HGR value obtained with 2.5% NaBH₄ using 10 mg catalyst was 7571 mL min^?1g^?1. The activation energy (Ea) for the g–C₃N₄–EDTA-H catalyst was found to be 32.2 kJ mol^?1 The reusability of the g–C₃N₄–EDTA-H catalyst shows a catalytic performance of 72% even after its fifth use.     

Influence of Rh nanoparticle size and composition on the photocatalytic water splitting performance of Rh/graphitic carbon nitride

The effect of Rh co-catalyst nanoparticle size for photocatalytic water splitting using graphitic carbon nitride (g-C₃N₄) as light absorber was investigated. Rh nanoparticles with sizes in the 4–9 nm range were synthesized and deposited on g-C₃N₄. The light-absorption properties of the g-C₃N₄ and the particle size of Rh supported on g-C₃N₄ were also not influenced by the catalyst synthesis procedures. Rh/C₃N₄ is active in the photocatalytic splitting of water using visible light. The activity for H₂ generation does not depend on Rh particle size. The results obtained point to two important design criteria for a successful photocatalyst: firstly, the surface of the semiconductor should support a sufficient number of Rh nanoparticles to remove the photogenerated electrons before their recombination with holes; secondly, the nanoparticles should be metallic in nature to catalyze the proton-electron transfer reaction to generate adsorbed H atoms. Surface oxidation of the Rh nanoparticles substantially lowers their photocatalytic activity.     

One-pot calcination preparation of graphene/g–C3N4–Co photocatalysts with enhanced visible light photocatalytic activity

Photocatalytic technology for hydrogen evolution from water splitting and pollutant degradation is one of the most sustainable methods. Here, the graphene/g–C₃N₄–Co composite materials have been prepared by one-pot calcination method. The results show that g-C₃N₄ grow on the surface of graphene and form a sandwich structure, meanwhile, the introduction of Co increases the active sites, which promotes the photocatalytic performance. The influences of graphene and Co content on photocatalytic activity were also studied by UV–visible spectrophotometry (DRS), photoluminescence spectroscopy (PL), photocurrent, degradation MB, and hydrogen production. The apparent reaction rate constant k of graphene/g–C₃N₄–Co (3%) is 0.946 h⁻¹, which is 4.90 and 2.18 times faster than g-C₃N₄ and graphene/g-C₃N₄, respectively. And the hydrogen production rate of graphene/g–C₃N₄–Co (3%) (892.3 μmol h⁻¹ g⁻¹) is 3.53 and 1.61 times higher than g-C₃N₄ and graphene/g-C₃N₄, respectively.     

Platinum supported on hydroxyl-grafted poly (3,4-ethylenedioxythiophene)-modified RuCo,N-tridoped bamboo-like carbon nanotubes for direct methanol fuel cell

The development of highly active and efficient heterogeneous catalytic oxidation system has become an attractive research field. In this paper, a catalyst (RuCo/N-CNT@PEDOT-OH/Pt) from platinum nanoparticles (Pt NPs) supported on hydroxyl-grafted poly(3,4-ethylenedioxythiophene) (PEDOT–OH)-modified RuCo, N-tridoped bamboo-like carbon nanotubes (RuCo/N-CNT) are used for direct methanol fuel cell (DMFC). The electrocatalytic activity of RuCo/N-CNT@PEDOT-OH/Pt is systematically compared with RuCo/N-CNT/Pt (Pt NPs supported on RuCo/N-CNT without PEDOT-OH) in the methanol oxidation reaction (MOR). The growth mechanism of carbon nanotubes and the role of heteroatom doping in the electrocatalytic process is explored. The catalysts show excellent electrocatalytic performance with high stability for MOR. It is found that the mass activity (MA) of the RuCo/N-CNT@PEDOT-OH/Pt (1961.3 mA mg^?1_Pt) for MOR was higher than that of RuCo/N-CNT/Pt (1470.1 mA mg^?1_Pt) and the commercial Pt/C catalysts (281.0 mA mg^?1_Pt), indicating the positive effect of the PEDOT-OH in the electrocatalytic MOR. In addition, density functional theory (DFT) calculations verify the possible mechanism pathways of the obtained RuCo/N-CNT@PEDOT-OH/Pt catalyst. This presented catalyst offers new inspiration for designing efficient electrocatalysts for methanol oxidation.     

Facile construction of composition-tuned ruthenium-nickel nanoparticles on g-C3N4 for enhanced hydrolysis of ammonia borane without base additives

Developing high-efficiency and low-cost catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is significant and critical for the exploitation and utilization of hydrogen energy. Herein, the in-situ fabrication of well-dispersed and small bimetallic RuNi alloy nanoparticles (NPs) with tuned compositions and concomitant hydrolysis of AB are successfully achieved by using graphitic carbon nitride (g-C₃N₄) as a NP support without additional stabilizing ligands. The optimized Ru₁Ni_7.5/g-C₃N₄ catalyst exhibits an excellent catalytic activity with a high turnover frequency of 901 min^?1 and an activation energy of 28.46 kJ mol^?1 without any base additives, overtaking the activities of many previously reported catalysts for AB hydrolysis. The kinetic studies indicate that the AB hydrolysis over Ru₁Ni_7.5/g-C₃N₄ is first-order and zero-order reactions with respect to the catalyst and AB concentrations, respectively. Ru₁Ni_7.5/g-C₃N₄ has a good recyclability with 46% of the initial catalytic activity retained even after five runs. The high performance of Ru₁Ni_7.5/g-C₃N₄ should be assigned to the small-sized alloy NPs with abundant accessible active sites and the synergistic effect between the composition-tuned Ru–Ni bimetals. This work highlights a potentially powerful and simple strategy for preparing highly active bimetallic alloy catalysts for AB hydrolysis to generate hydrogen.     

Magnetic Fe3C@C nanoparticles as a novel cocatalyst for boosting visible-light-driven photocatalytic performance of g-C3N4

In photocatalytic field, it is a significant challenge to synthesize cocatalyst with high performance, noble-metal free and facile methods to recycle. Herein, carbon layer coated Fe₃C (Fe₃C@C) nanoparticles were prepared by one-step method and for the first time utilized as highly efficient cocatalysts for improving visible-light-driven hydrogen evolution activity of g-C₃N₄. The photocatalytic hydrogen evolution rate of optimal Fe₃C@C/g-C₃N₄ was about 27.2 times of bare g-C₃N₄ samples. Furthermore, the Fe₃C@C/g-C₃N₄ composite catalyst showed excellent stability and reusability. The apparent quantum yield (AQY) of the optimized FeC@C/g- C₃N₄ reaches 0.501% and 0.124% at 400 nm and 420 nm, respectively. The AQY of the FeC@C/g- C₃N₄ is 26.2 times higher than that of g-C₃N₄ at 400 nm Fe₃C@C has an extraordinary cocatalytic effect for g-C₃N₄ photocatalytic hydrogen evolution mainly due to three aspects: Firstly, the Fe₃C acts as a trap to lure electrons because of its lower Fermi energy level and higher conductivity, which can increase the hydrogen production activity by trapping the photogenerated electrons produced by g-C₃N₄; Secondly, the coated carbon layer can provide chemical protection for Fe₃C nanoparticles and promote the transfer of photogenic electrons, thus further improving the efficiency and stability of photocatalytic hydrogen production; Thirdly, the strong magnetic property of Fe₃C@C nanoparticles gives Fe₃C@C/g-C₃N₄ photocatalysts the advantages of low cost and high recovery efficiency. It is believed that this work provides a new strategy and possibility for the application of photocatalytic hydrogen production.     

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.     

A facile one-step strategy to construct 0D/2D SnO2/g-C3N4 heterojunction photocatalyst for high-efficiency hydrogen production performance from water splitting

Fabricating 0D/2D heterojunctions is considered to be an efficient mean to improve the photocatalytic activity of g-C₃N₄, whereas their applications are usually restricted by complex preparation process. Here, the 0D/2D SnO₂/g-C₃N₄ heterojunction photocatalyst is prepared by a simple one-step polymerization strategy, in which SnO₂ nanodots in-situ grow on the surface of g-C₃N₄ nanosheets. It shows the outstanding photocatalytic H₂ production activity relative to g-C₃N₄ under the visible light, which is due to the formation of 0D/2D heterojunction significantly contributing to the separation of photogenerated charge carriers. In particular, the H₂ production rate over the optimal SnO₂/g–C₃N₄–1 sample is 1389.2 μmol h⁻¹ g⁻¹, which is 6.06 times higher than that of g-C₃N₄ (230.8 μmol h⁻¹ g⁻¹). Meanwhile, the AQE value of H₂ production over the SnO₂/g–C₃N₄–1 sample reaches up to a maximum of 4.5% at 420 nm. This work develops a simple approach to design and fabricate g–C₃N₄–based 0D/2D heterojunctions for the high-efficiency H₂ production from water splitting.