g-C3N4 Particles Research Articles

Fe-Doped g-C3N4/Bi2MoO6 Heterostructured Composition with Improved Visible Photocatalytic Activity for Rhodamine B Degradation.

The binary heterostructured semiconducting visible light photocatalyst of the iron-doped graphitic carbon nitride/bismuth molybdate (Fe-g-C3N4/Bi2MoO6) composite was prepared by coupling with Fe-doped g-C3N4 and Bi2MoO6 particles. In the present study, a comparison of structural characteristics, optical properties, and photocatalytic degradation efficiency and activity between Fe-doped g-C3N4 particles, Bi2MoO6 particles, and Fe-g-C3N4/Bi2MoO6 composite was investigated. The results of X-ray diffraction (XRD) examination indicate that the hydrothermal Bi2MoO6 particles have a single orthorhombic phase and Fourier transform infrared (FTIR) spectroscopy analysis confirms the formation of Fe-doped g-C3N4. The optical bandgaps of the Fe-doped g-C3N4 and Bi2MoO6 particles are 2.74 and 2.73 eV, respectively, as estimated from the Taut plots obtained from UV-Vis diffuse reflectance spectroscopy (DRS) spectra. This characteristic indicates that the two semiconductor materials are suitable for absorbing visible light. The transmission electron microscopy (TEM) micrograph reveals the formation of the heterojunction Fe-g-C3N4/Bi2MoO6 composite. The results of photocatalytic degradation revealed that the developed Fe-g-C3N4/Bi2MoO6 composite photocatalyst exhibited significantly better photodegradation performance than the other two single semiconductor photocatalysts. This property can be attributed to the heterostructured nanostructure, which could effectively prevent the recombination of photogenerated carriers (electron-hole pairs) and enhance photocatalytic activity. Furthermore, cycling test showed that the Fe-g-C3N4/Bi2MoO6 heterostructured photocatalyst exhibited good reproducibility and stability for organic dye photodegradation.

Graphitic carbon nitride as a novel anticancer agent: potential mechanisms and efficacy in prostate cancer and glioblastoma treatment.

Carbon-derived compounds are gaining traction in the scientific community because of their unique properties, such as conductivity and strength, and promising innovations in technology and medicine. Graphitic nitride carbon (g-C3N4) stands out among these compounds because of its potential in antitumor therapies. This study aimed to assess g-C3N4's antitumor potential and cytotoxic mechanisms. Prostate cancer (DU-145) and glioblastoma (U87) cell lines were used to evaluate antitumor effects, whereas RAW 264.7 and HFF-1 non-tumor cells were used for selectivity evaluation. The synthesized g-C3N4 particles underwent comprehensive characterization, including the assessment of particle size, morphology, and oxygen content, employing various techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The results indicated that g-C3N4 significantly affected tumor cell proliferation and viability, exhibiting high cytotoxicity within 48 h. In non-tumor cells, minimal effects on proliferation were observed, except for damage to the cell membranes of RAW 264.7 cells. Moreover, g-C3N4 changed the cell morphology and ultrastructure, affecting cell migration in U87 cells and potentially enhancing migration in RAW 264.7 cells. Biochemical assays in Balb/C mice revealed alterations in alanine aminotransferase, aspartate aminotransferase, and amylase levels. In conclusion, g-C3N4 demonstrated promising antitumor effects with minimal toxicity to non-tumor cells, suggesting its potential in neoplasm treatment.

Combustion Characteristics of r-GO/g-C3N4/LaFeO3 Nanohybrids Loaded Fuel Droplets

ABSTRACT Graphene oxide (GO), reduced graphene oxide (r-GO) and graphitic carbon nitride (g-C3N4) are two-dimensional carbon-based nanosheets that show promise in reducing emissions with their superior catalytic activity in capturing species such as NOx and CO2 thanks to their oxygen-based functional groups and active edges on their surfaces. These active surfaces also provide a scheme for the substitution of materials with high calorific value or high catalytic activity for combustion. This study focuses on the fabrication of functional nanohybrid structures customized for combustion with LaFeO3 metal oxide nanoparticles substituted on these nanosheets and their effect on the combustion behavior of gasoline. The fabrication of r-GO/g-C3N4/LaFeO3 nanohybrid structures was carried out by a two-step hydrothermal method. The structural characterizations of the samples were confirmed by SEM and XRD analyses and their chemical states were confirmed by Raman and XPS techniques. Combustion experiments were carried out by droplet scale combustion of gasoline-based nanofuel droplets containing dilute (0.2 wt.%) and high (0.7 wt.%) concentrations of GO, r-GO, g-C3N4, g-C3N4/LaFeO3 and r-GO/g-C3N4/LaFeO3 nanoparticles. The experimental process was recorded with a high-speed camera and a thermal camera. The nanofuel droplets containing 0.2 wt.% g-C3N4/LaFeO3 nanohybrid structures had the highest maximum flame temperature of 519 K, and the nanofuel droplets containing 0.7 wt.% r-GO/g-C3N4/LaFeO3 particles had the highest maximum aggregate temperature of 1177 K. The ignition delay time decreased for all droplets with 0.2 wt.% and 0.7 wt.% particle loadings. At 0.2 wt.% concentration, g-C3N4 doped fuel droplets exhibited the lowest extinction time, while at 0.7 wt.% concentration, the lowest extinction time was measured for r-GO/g-C3N4/LaFeO3 doped fuel droplets. Fuel droplets containing g-C3N4 particles had the highest burning rate and were the fastest extinguishing fuel droplets in the electric field. In this study, it has been demonstrated that the combustion rate and energy value of hydrocarbon fuels can be increased and soot formation can be reduced at the same time with the new generation of graphene-based functional materials to be created, and thus, many combustion problems can be solved simultaneously with these functional particles.

Composite photocatalyst C3N4/BiVO4 for adsorption/photocatalytic degradation of drugs in water

C3N4/BiVO4 composites as co-photocatalyst were successfully synthesized via hydrothermal method by varying the weight ratio of g-C3N4/BiVO4. The prepared samples were characterized using X-ray diffraction instrument, scanning electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The morphological properties of composites show that g-C3N4 particles is deposited on the surface of BiVO4 while the crystal structure study shows that co-catalysts are existed by X-ray diffraction pattern. The photocatalytic degradation shows improvement by the composite with a ratio of 5% g-C3N4/BiVO4, the adsorption/photodegradation of Rhodamine B and Methyl Orange were about 97% and 88%, respectively within 40 min. The result indicates that g-C3N4/BiVO4 are paired their properties which are adsorption/photocatalyst, consequently, efficient spatial charge carrier separation. This finding was applied to remove ciprofloxacin and paracetamol in water. about 65% of paracetamol was removed from water compared with 15% of ciprofloxacin, this result revealing that excellent photodegradation of paracetamol by 5% g-C3N4/BiVO4 composite.

Hydrophobic electroless nickel phosphorus-graphene carbon nitride coating on AISI 4140 steel with enhanced hardness and scratch resistance

The present article explores the ability of synthesized graphene carbon nitride (g-C3N4) towards the improvement of microstructure, surface energy, surface hardness, and scratch resistance of electroless nickel phosphorus-graphene carbon nitride (NiP/g-C3N4) coated AISI 4140 steel. Comparative studies were conducted to evaluate how the g-C3N4 concentrations affect the physical, mechanical, and surface properties of electroless NiP/g-C3N4 composite coating. Morphology analysis confirmed the nodular formation for the NiP/g-C3N4 composite coating due to the nucleation phenomenon induced by the g-C3N4 particle. Further, the g-C3N4 particle has favoured the growth of the Ni crystal, which is confirmed in the X-ray diffractometer study. In comparison, the higher weight percentage of g-C3N4 particles has increased the hardness, residual stress, surface roughness, and contact angle of the electroless NiP/g-C3N4 composite coating. The maximum tensile residual stress had a positive impact on controlling the formation of slippage cracks for the NiP/g-C3N4 composite coating, which is confirmed in the fractography analysis of the hardness indentation. Furthermore, the detailed failure mechanisms of the coatings during the hardness and scratch test of NiP/g-C3N4 composite coatings were precisely discussed and compared with the particle-free NiP coating.

Effect of montmorillonite and humic acid on cotransport of g-C3N4 and lead: The role of triazine ring in lead adsorption and deposition in soil components

In the past few years, Graphitic carbon nitride (g-C3N4) has been produced on a large scale and has been widely used because of its excellent optical properties and physicochemical stability. It is easy to ignore the risk of g-C3N4 transport in the environment, including soil and groundwater, due to the non-toxicity of metals. Based on this situation, we investigated the effects of pumping flow rate, ionic strength, and the presence of lead (Pb) on the transport behavior of g-C3N4 in quartz sand, montmorillonite, and humic acid-coated sand through column experiments. The retention of g-C3N4 in the media and the adsorption mechanism of Pb onto g-C3N4 were analyzed by FTIR and XPS. The results showed that fast flow rate and low ionic strength were favorable conditions for the transport of g-C3N4. The cotransport experiment results showed that Pb reduced the outflow of g-C3N4 by more than 50%. Contrarily, 6.95%, 0.43%, and 11.01% Pb were hindered in quartz sand, montmorillonite, and humic acid-coated sand due to the presence of g-C3N4. Compared with the uncontaminated media, the recoveries of g-C3N4 in Pb contaminated quartz sand, montmorillonite, and humic acid-coated sand were reduced by 0.34%, 5.86%, and 15.34%, respectively. Concomitantly, which were attributed to the special triazine ring structure and the abundant bonding modes with soil components and Pb, g-C3N4 particles were easier to deposit in montmorillonite and humic acid-coated sand, and could be used as the carrier to release 6.70% and 5.64% Pb from contaminated quartz sand and humic acid-coated sand.

Enhanced Visible Light Photocatalytic Activity of g-C3N4/SiO2@TiO2 Heterojunction Fabricated by Hydrothermal Synthesis

Photocatalysts that can utilize sunlight energy have attracted attention. In this study, g-C3N4 and mesoporous SiO2@TiO2 particles were mixed by hydrothermal synthesis. g-C3N4 was made by a simple method of directly heating melamine. Mesoporous SiO2@TiO2 was prepared using the stover method. These two types of particles were then mixed by hydrothermal synthesis. Hydrothermal synthesis reduced the size of the g-C3N4 particles, and they bound more closely with the TiO2 particles. The degradation of methylene blue dye by visible light was performed to evaluate the organic degradation of the mixed particles. In addition, the mixed particles were formed into a thin film by the spin-coating method. The film's methylene blue degradation performance and the film's power generation performance in a battery were evaluated. The film showed high convenience in the practical application of photocatalytic degradation of organic pollutants because it can be easily separated from the treated liquid after organic matter degradation.

Fast g-C3N4 sonocoated activated carbon for enhanced solar photocatalytic oxidation of organic pollutants through Adsorb & Shuttle process

To solve low mass transfer in photocatalytic technology for water treatment, the combination of photoactive nanoparticles with highly adsorptive materials has been regarded as a successful approach. The optimization of photoactive particle coating in terms of dispersion on the surface of adsorbing support is the main key to reach a maximum synergism for pollutants removal. This study discusses the coating of as-prepared biomass based activated carbon by g-C3N4 using three routes, namely ball milling (AC-CN@BM), physical stirring (AC-CN@Phy) and ultrasonic assisted coating (AC-CN@US). The coating mechanisms by different processes were discussed using different characterization techniques. Ball milling based coating provides good g-C3N4 dispersion on the surface of AC, however, a partial degradation of g-C3N4 structure and a lower surface area were confirmed by FTIR, XRD and BET analysis. Physically designed sample shows a significant agglomeration of particles on the surface of AC. However, ultrasonic coating provides excellent distribution of g-C3N4 and high surface of the composite. In terms of photoactivity, AC-CN@BM exhibits the lowest adsorption and photocatalytic activity under solar light for the removal of ciprofloxacin. AC-CN@Phy showed medium performance, but less physical stability of g-C3N4 particles on AC, leading to their partial release. AC-CN@US showed the highest efficiency and stability after using; suggesting the good combination between g-C3N4 and AC, which in turn maximizes the removal of ciprofloxacin via Adsorb & shuttle process. The overall costs of composite, including the starting elements and the coating ultrasonic process are relatively low and green as compared to commonly reported routes.

Euplectella aspergillum inspired PPAN@g-C3N4 fibrous membrane with abundant micro/nano pores for high-throughput wastewater purification

Integrating photocatalytic degradation and membrane separation is a crucial approach to water purification. Here, inspired by Euplectella aspergillum, we presented an electrospinning fibrous membrane containing polyacrylonitrile (PAN), graphitic carbon nitride (g-C3N4) particles, and polyvinylpyrrolidone (PVP). The g-C3N4 particles undertook the task of photocatalytic degradation for various contaminants. The PVP molecules assumed the role of pore-forming agent for providing additional channels for high-throughput wastewater purification. Furthermore, the micro/nano porous structure of the PPAN@g-C3N4 fibers promoted the exposure of the photocatalytic active center of the g-C3N4 particles, improving the light absorption capacity and enhancing photocatalytic performance. Hence, the prepared PPAN@g-C3N4 fibrous membrane possessed excellent separation properties for the oil/water mixture (53,555 ± 3241 L m−2 h−1 bar−1) and oil-in-water emulsion (103,689 ± 13,286 L m−2 h−1 bar−1), and maintained its initial separation performance after cyclic separation. Moreover, the membrane showed excellent photocatalytic performance for different pollutants, among which the photocatalytic efficiency of RhB, MB, and MG was about 100 %. After 7 consecutive photocatalytic degradation of RhB, the efficiency remained above 95 %. Meanwhile, the antibacterial efficiency was more than 87 %. The combination of high-throughput separation performance and excellent catalytic performance exemplifies its potential attractiveness for practical wastewater purification.

Efficient electrochemical NO reduction to NH3 over metal-free g-C3N4 nanosheets and the role of interface microenvironment

The ever-increasing NO emission has caused severe environmental issues and adverse effects on human health. Electrocatalytic reduction is regarded as a win-win technology for NO treatment with value-added NH3 generation, but the process is mainly relied on the metal-containing electrocatalysts. Here, we developed metal-free g-C3N4 nanosheets (deposited on carbon paper, named as CNNS/CP) for NH3 synthesis from electrochemical NO reduction under ambient condition. The CNNS/CP electrode afforded excellent NH3 yield rate of 15.1 μmol h−1 cm−2 (2180.1 mg gcat−1 h−1) and Faradic efficiency (FE) of ∼41.5 % at − 0.8 and − 0.6 VRHE, respectively, which were superior to the block g-C3N4 particles and comparable to the most of metal-containing catalysts. Moreover, through adjusting the interface microenvironment of CNNS/CP electrode by hydrophobic treatment, the abundant gas-liquid-solid triphasic interface improved NO mass transfer and availability, which enhanced NH3 production and FE to about 30.7 μmol h−1 cm−2 (4424.2 mg gcat−1 h−1) and 45.6 % at potential of − 0.8 VRHE. This study opens a novel pathway to develop efficient metal-free electrocatalysts for NO electroreduction and highlights the importance of electrode interface microenvironment in electrocatalysis.

In situ growth g-C3N4 particles on carbon fiber cloth as flexible and easily reusable visible-light-driven photocatalysts

Graphitic carbon nitride (g-C3N4) powder has been extensively applied for photocatalysis, while its practical application is impeded by reusability problems. To solve this issue, we have fabricated flexible and easily recyclable photocatalysts by in situ growing g-C3N4 on carbon fiber cloth (CFc) via dip-coating and following a pyrolysis method. The obtained cloth (area: 4 cm × 4 cm) consisted of carbon fiber (diameter: ∼20 μm) bunches covered by g-C3N4 nanoparticles. CFc/g-C3N4 exhibits a broad absorption spectrum with an absorption edge of 460 nm. CFc/g-C3N4 can degrade 94.8 % Rhodamine B (RhB) in 80 min and 97.3 % parachlorophenol (4-CP) in 100 min reaction, respectively under visible light illumination. Moreover, CFc/g-C3N4 maintains good photocatalytic efficiency of 89.7 % after four times recycling tests. Therefore, CFc/g-C3N4 has the potential for practical photocatalysis application.

Enhanced degradation of quinoline in three-dimensional electro-Fenton system using catalytic Fe-Co-Ni-P/g-C3N4 particles

Enhanced degradation of quinoline in three-dimensional electro-Fenton system using catalytic Fe-Co-Ni-P/g-C3N4 particles

Use of Heteroatom-Doped g-C3N4 Particles as Catalysts for Dehydrogenation of Sodium Borohydride in Methanol

Here, graphitic carbon nitride (g-C3N4) was synthesized from melamine, doped with heteroatoms, such as B, S, and P reported using boric acid, sulfur, and phosphorous red as dopants, respectively. The catalytic performances of g-C3N4, and heteroatom-doped g-C3N4 (H@g-C3N4 (H=B, S or P) particles as catalysts in the dehydrogenation of sodium borohydride (NaBH4) in methanol to generate hydrogen (H2) were investigated. The prepared g-C3N4-based structures were used as catalysts for hydrogen (H2) production in the dehydrogenation reaction of sodium borohydride (NaBH4) in methanol. The catalytic performance of H@g-C3N4 (H=B, S or P) structures in the dehydrogenation reaction of sodium borohydride (NaBH4) in methanol was determined to be higher than the catalytic performance of the bare g-C3N4 structure. The hydrogen generation rate (HGR) values were calculated for the reactions catalyzed by B@g-C3N4, P@g-C3N4, and S@g-C3N4 as 609 ± 48, 699 ± 48, and 429 ± 55 mL H2/g of cat.min, respectively, which is only 282 ± 11 mL H2/g of cat.min for the native g-C3N4-catalyzed one. The activation energies (Ea) were found to be relatively low, such as 31.2, 26.9, and 31.2 kJ/mol, for the reactions catalyzed by B@g-C3N4, P@g-C3N4, and S@g-C3N4, respectively. In addition, in the reuse studies, it was concluded that B@g-C3N4, P@g-C3N4, and S@g-C3N4 catalysts can readily complete the reaction with 100% conversion, even in five consecutive uses, and afforded promising potential with more than 80% activity for each use.

Liquid-solid phase separation-generated multifunctional light-weight modification layer of g-C3N4/carbon endowing 5 V cathode material graphite flakes with high capacity and cyclicability simultaneously

Nowadays metal oxide coatings become one of the dominant ways to suppress electrolyte decomposition and consequantly improve cyclicability of high-voltage cathode materials for high energy-density batteries. However electrochemically inert nature and relatively high density of the metal oxides inevitably reduce cathode capacities. Meanwhile weak interfacial binding may induce desorption of the metal oxides during charge/discharge cycling. Herein a new strategy of light-weight g-C3N4/carbon coordinative modification of 5 V cathode material graphite flakes (GF) for dual-ion batteries is provided with aim to maintain graphite capacity and enhance interfacial binding strength simultaneously. Liquid-solid phase separation is utilized to generate multifunctional unique structure of the modification layer consisting of ultrafine g-C3N4 particles embedded homogeneously in carbon matrix, endowing the modified GF with high capacity and cyclicability for anion PF6─ storage simultaneously. A capacity enhancement of ~11% (1 C) is realized compared with that of TiO2/carbon modified GF, demonstrating superiority of the light-weight modification. Meanwhile capacity retention reaches 87% after 1500 charge/discharge cycles (5 C), exhibiting excellent cyclicability. The liquid-solid phase separation is an efficient way to generate homogeneous mixtures. Furthermore, the strategy of light-weight g-C3N4/carbon modification may provide a general way to improve capacity and cyclicability of other high-voltage cathode materials simultaneously.

Energy band tuning induced by g-C3N4 interface engineering for efficient and stable perovskite solar cells

Energy band tuning in perovskite solar cells (PSCs) was established via an interface engineering approach involving graphitic carbon nitride (g-C3N4) between TiO2 electron transport layer (ETL) and CH3NH3PbI3 perovskite absorber. The introduction of g-C3N4 resulted in simultaneous energy bands downshifts and conduction bands alignment to − 4.4 eV of the TiO2 and the perovskite, which facilitated the electron transfer to the anode without any energy loss and enhanced the short-circuit photocurrent density (Jsc). Moreover, the proposed modification provided a more hydrophobic substrate which favored the growth of perovskite films with better crystallinity and higher robustness against oxygen and humidity. The new strategy led to perovskite solar cells with an optimized overall photovoltaic performance including a power conversion efficiency (PCE) exceeding 20%. The g-C3N4 particles hindered perovskite degradation and the resulting PSCs retained 98% of their initial PCE after 3000 h under dark and relative low humidity (RH~20%) conditions.

Construction and investigation of graphitic carbon nitride/expanded perlite composite photocatalyst with floating ability

Using melamine as the precursor of g-C3N4 and expanded perlite (EP) as the carrier, a kind of floating g-C3N4/expanded perlite composites (CN/EP-x, where x was denoted as 1, 2, 4 and 6, respectively, corresponding to the mass ratio of melamine to EP 1:2, 2:1, 4:1 and 6:1) were synthesized by cooperating wet-chemistry method with a unique heat treatment schedule, which aimed to enhance the g-C3N4 loading ratio and construct a tightly interface between g-C3N4 and EP. The phase composition, microstructure, element composition, optical property, etc. of the g-C3N4/EP composites were investigated, and their photocatalytic performances vs. the mass ratio of melamine to EP (loading ratio of g-C3N4) were evaluated through photo-degrading Rhodamine B (RhB) aqueous solution. It is found that g-C3N4 immobilized on the surface or embedded into the open pores of EP, which were beneficial to the interface bonding strength between g-C3N4 and EP. With the increasing of the mass ratio of melamine, the loading ratio of g-C3N4 in CN/EP-x composite increased gradually, and the specific surface area of the composite increased step by step but then dropped for CN/EP-6 composite owing to the intensified agglomeration of g-C3N4 particles. The photocatalytic performance of CN/EP-x composites also improved gradually and achieved the optimum for the CN/EP-4 composite, then reduced for the CN/EP-6 composite. CN/EP-4 composite (0.35 g) degraded 94 % of RhB molecules (10 mg/L, 100 mL) after visible light illumination for 120 min. The reduced band gap, improved separation efficiency of holes and electrons, enhanced photo-current response, reduced electron transfer resistance, as well as the enhanced specific surface area were responsible for the optimum photocatalytic performance of CN/EP-4 composite. Moreover, CN/EP-4 composite exhibited excellent floating performance, stability and reusability. After four degradation cycles, the removal rate of RhB by CN/EP-4 composite still achieved 83 %. This work will provide a new insight into synthesizing floating composite photocatalysts for the future practical application.

Integration of g-C3N4 into cellulose/graphene oxide foams for efficient photocatalytic Cr(VI) reduction

Graphitic carbon nitride (g-C3N4) exhibits unique optical properties and it is regarded as an excellent photocatalyst. However, powdered g-C3N4 suffers from limited carrier mobility and poor recyclability. Here, g-C3N4 powders are integrated into cellulose/graphene oxide (GO) matrix to obtain a convenient and three-dimensional foam via a freeze-drying method. Owing to the formation of crosslinks between and g-C3N4 and carboxylic cellulose, the g-C3N4 particles attach tightly to the foam skeleton and are uniformly dispersed. As-prepared foams have good mechanical flexibility and superior water stability. Visible light driven reduction of Cr(VI) was utilized to evaluate the photocatalytic performance. The optimal sample (CG-3 with 60 wt% g-C3N4 loading) can reduce 98% of Cr(VI) within 3 h, even performs better than powdered g-C3N4 counterpart. The presence of GO facilitates the light absorption and promotes the stability of composite films. Moreover, the composite foams are facile to recycle without complex separation procedures. The CG-3 has no significant loss of its original reduction performance after 9 cycles, proving desirable reusability. This work provides a solution for powder catalyst recovery and inspires the materials design on g-C3N4.

Highly efficient hydrogen production under visible light over g-C3N4-based photocatalysts with low platinum content

The successive combination including thermolysis of melamine cyanurate complex, chemisorption of platinum from the solution of the labile nitratocomplex and, finally, reductive treatment with hydrogen was implemented to obtain highly active Pt/g-C3N4 photocatalysts (0.01–0.5 wt% of Pt). The prepared in this way materials evinces photocatalytic activity in hydrogen evolution reaction from TEOA/water solutions with the superb rate of H2 evolution per platinum atom loaded (1560 h−1) and the net rates being among the highest reported to date values (11 mmol·g−1·h−1). Such a remarkable performance correlates with the structure of these materials where the branchy net of the pores provides easy access of reagents to and ejection of products from the nanoparticulated Pt co-catalysts. A crucial contribution to the formation of the noted Pt/g-C3N4 morphology ascribed to the self-catalyzed hydrogenation of the Pt/g-C3N4 composites resulting in “scarifying” of the g-C3N4 particles preferentially at the surface layer where Pt species are located. Taking into account the high productivity of the synthesized Pt/C3N4 materials and robustness of the preparation method this approach can be convenient for the large-scale applications that were successfully demonstrated under pilot installation (total volume 1 l) with the fuel cell (PEMFC with max output 1 W) as a hydrogen consumer. Evaluation of the productivity of the large-scale reactor for hydrogen production with a scaled-up installation was carried out. This study also grants a new vision on developing expandable synthetic approaches to enhance the performance of carbon nitride-based photocatalysts and at the same time mitigate the noble metal co-catalysts usage.

G-C3N4 particles with boron and oxygen dopants/carbon vacancies for efficient dehydrogenation in sodium borohydride methanolysis

In the study, metal-free boron and oxygen incorporated graphitic carbon nitride (B and O doped g-C3N4) with carbon vacancy was successfully prepared and applied as a catalyst to the dehydrogenation of sodium borohydride (NaBH4) in methanol for the first time. The hydrogen generation rate (HGR) value was found to be 11,600 mL min−1g−1 by NaBH4 of 2.5%. This is 2.53 times higher than the g-C3N4 catalyst without the addition of B and O. The obtained activation energy was 25.46 kJ mol−1. X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), energy dispersive X-Ray analyser (EDX), Transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) analyses for characterization were performed. A possible mechanism of H2 production from the reaction using metal-free B and O doped g-C3N4 catalyst with carbon vacancy has been proposed. This study showed that g-C3N4 and its composites with doping atoms can be used effectively in H2 production by NaBH4 methanolysis.

Facile fabrication of P-doped g-C3N4 particles with nitrogen vacancies for efficient dehydrogenation of sodium borohydride methanolysis

The graphitic carbon nitride (g-C3N4) has become important in the field of environmental remediation with its metal-free and low-cost advantages. Here, for the first time in the literature, P doped graphitic carbon nitride (g-C3N4) was used in the dehydrogenation of sodium borohydride (NaBH4) methanolysis. The effects of interaction time with phosphoric acid (H3PO4), NaBH4 concentration, amount of catalyst and temperature were investigated. The best interaction time with phosphoric acid was found to be 12 h. There was a 2-fold increase in the HGR values obtained by increasing the amount of NaBH4 from 1.25% to 2.5%, while there was a less proportional increase with increasing the amount of NaBH4 from 2.5% to 5%. Depending on the increase in the amount of catalyst, there is a decrease in the completion times of this reaction. H2 production rate of NaBH4 methanolysis increases rapidly with increasing temperature. An HGR value of 8666 mL min−1 cat−1 using P doped g-C3N4 (10 mg) was found. The activation energy obtained for this metal-free catalyst was 30.29 kJ mol−1. Scanning electron microscopywith energy dispersive X-Ray analysis (SEM-EDX), X-ray photoelectron spectroscopy (XPS), Transmission electron microscope(TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) analyses were used for characterization. A possible reaction mechanism was proposed for the catalyst used in this methanolysis reaction. At the same time, repeatability experiments were carried out for the catalyst.