Ultrathin graphitic C3N4 nanosheet as a promising visible-light-activated support for boosting photoelectrocatalytic methanol oxidation
TL;DR: In this article, an ultrathin two dimensional (2D) g-C 3 N 4 nanosheet was used as support for the deposition of ultrasmall Pt nanoclusters.
Abstract: In this paper, ultrathin two dimensional (2D) g-C 3 N 4 nanosheet worked as support for the deposition of ultrasmall Pt nanoclusters. The average size of Pt nanocluster is about 3.2 nm. Firstly, the as-prepared Pt/g-C 3 N 4 modified electrode exhibited enhanced electrocatalytic ability in methanol oxidation reaction (MOR) compared to bare Pt nanoparticles. Moreover, when this electrode was upon visible light irradiation, higher performance of MOR was clearly observed compared to the traditional ambient electrocatalytic oxidation. This is owing to the synergistic effects of photocatalytic and electrocatalytic MOR together with the efficient interfacial charger transfer in Pt/g-C 3 N 4 . These results show that 2D ultrathin g-C 3 N 4 nanosheets can be used as promising photoactived support in the fields of solar and chemical energy conversion and also provide more insights into developing novel visible light photo-responsive electrode in direct methanol fuel cell.
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TL;DR: Owing to the interfacial interaction between BP and CN, efficient charge transfer occurred, thereby enhancing the photocatalytic performance, and the present results show that BP/CN is a metal-free photocatalyst for artificial photosynthesis and renewable energy conversion.
Abstract: In the drive toward green and sustainable chemistry, exploring efficient and stable metal-free photocatalysts with broadband solar absorption from the UV to near-infrared region for the photoreduction of water to H2 remains a big challenge. To this end, a binary nanohybrid (BP/CN) of two-dimensional (2D) black phosphorus (BP) and graphitic carbon nitride (CN) was designed and used as a metal-free photocatalyst for the first time. During irradiation of BP/CN in water with >420 and >780 nm light, solid H2 gas was generated, respectively. Owing to the interfacial interaction between BP and CN, efficient charge transfer occurred, thereby enhancing the photocatalytic performance. The efficient charge-trapping and transfer processes were thoroughly investigated with time-resolved diffuse reflectance spectroscopic measurement. The present results show that BP/CN is a metal-free photocatalyst for artificial photosynthesis and renewable energy conversion.
857 citations
TL;DR: In this article, a direct Z-scheme g-C3N4/SnS2 heterojunction was constructed by depositing SnS2 quantum dots onto the g-c3n4/snS2 surface in situ via a simple one-step hydrothermal method.
671 citations
TL;DR: In this paper, a metal-free heterostructure photocatalyst constructed by boron nitride quantum dots (BNQDs) and ultrathin porous g-C3N4 (UPCN) was successfully developed for overcoming these defects.
Abstract: Graphitic carbon nitride (g-C3N4) has enormous potential for photocatalysis, but only possesses moderate activity because of excitonic effects and sluggish charge transfer. Herein, metal-free heterostructure photocatalyst constructed by boron nitride quantum dots (BNQDs) and ultrathin porous g-C3N4 (UPCN) was successfully developed for overcoming these defects. Results showed that the BNQDs loaded UPCN can simultaneously promote the dissociation of excitons and accelerate the transfer of charges owing to the negatively charged functional groups on the surface of BNQDs as well as the ultrathin and porous nanostructure of g-C3N4. Benefiting from the intensified exciton dissociation and charge transfer, the BNQDs/UPCN (BU) photocatalyst presented superior visible-light-driven molecular oxygen activation ability, such as superoxide radical ( O2−) generation and hydrogen peroxide (H2O2) production. The average O2− generation rate of the optimal sample (BU-3) was estimated to be 0.25 μmol L−1 min−1, which was about 2.3 and 1.6 times than that of bulk g-C3N4 and UPCN. Moreover, the H2O2 production by BU-3 was also higher than that of bulk g-C3N4 (22.77 μmol L−1) and UPCN (36.13 μmol L−1), and reached 72.30 μmol L−1 over 60 min. This work reveals how rational combination of g-C3N4 with BNQDs can endow it with improved photocatalytic activity for molecular oxygen activation, and provides a novel metal-free and highly efficient photocatalyst for environmental remediation and energy conversion.
512 citations
TL;DR: In this paper, a hierarchical hetero-structures dropcasted on carbon nitride (C3N4) anodes have been visualised by SEM and their catalytic performance have been examined in methanol electrooxidation reaction (MOR) under alkaline conditions.
Abstract: Ni, Cu and Cu–Ni nanostructures have been fabricated and homogeneously embedded on ultrathin two-dimensional (2D) carbon nitride (g-C3N4), and the surface morphology and composition of the resulting hybrid nanostructures were studied by XRD, TEM, HRTEM-elemental mapping, Raman spectroscopy and XPS. The new hierarchical hetero-structures dropcasted on GC anodes have been visualised by SEM and their catalytic performance have been examined in methanol electrooxidation reaction (MOR) under alkaline conditions. Nanosized Ni particles dispersed finely over g-C3N4 are very active electrocatalysts with MOR onset at potential 0.35 V and charge transfer resistance 0.12 kΩ. The stability of modyfied GC electrodes, examined under chronoamperometric conditions showed that for electrode loading with 4% (wt. %) of NiO the stable current density ca. 36 A g−1 (12 A cm2) was obtained during whole experiment (up to 160 min). For all catalyst studied the curent density obtained during MOR reaction was enhanced when electrode was iluminated by UV light λ∼400 nm, and the highest value were obtained for 4% Ni/CN catalyst ca. 127 A g−1 (22 A cm2). The Cu incorporation in the hybrid material evoke loss of activity mostly due to Cu+ irreversible reduction/oxidation to Cu° and Cu2+, CuO segregation and influencing electron transfer process which results in the increasing in the redox potential. These results represent an important step towards light-enhanced electro-reactive systems and sensors in which heterojunction formation can facilitate electron-hole separation and enable more efficient energy transfer.
217 citations
TL;DR: In this paper, a facial, one-step soft templating method to synthesize the hollow mesoporous g-C3N4 spheres with high surface area and high porosity was developed, which took advantage of both supramolecular assembly of cyanuric acid and melamine through hydrogen bonds and the structure-directing character of ionic liquid.
187 citations
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TL;DR: The photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal coc atalysts, and Z-scheme heterojunctions.
Abstract: Semiconductor-based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g-C3N4) for visible-light photocatalytic water splitting, g-C3N4 -based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g-C3N4 -based photocatalysts, including the fabrication and nanostructure design of pristine g-C3N4 , bandgap engineering through atomic-level doping and molecular-level modification, and the preparation of g-C3N4 -based semiconductor composites. Also, the photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal cocatalysts, and Z-scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g-C3N4 -based photocatalysts are highlighted.
2,868 citations
TL;DR: Graphene and graphitic carbon nitride composite photocatalysts were prepared by a combined impregnation−chemical reduction strategy involving polymerization of melamine in the presence of graphene oxide (precursors) and hydrazine hydrate (reducing agent), followed by thermal treatment at 550 °C under flowing nitrogen as mentioned in this paper.
Abstract: Graphene and graphitic carbon nitride (g-C3N4) composite photocatalysts were prepared by a combined impregnation−chemical reduction strategy involving polymerization of melamine in the presence of graphene oxide (precursors) and hydrazine hydrate (reducing agent), followed by thermal treatment at 550 °C under flowing nitrogen. The resulting graphene/g-C3N4 composite photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, UV−visible spectrophotometry, nitrogen adsorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy. The transient photocurrent response was measured for several on−off cycles of intermittent irradiation. The effect of graphene content on the rate of visible-light photocatalytic hydrogen production was studied for a series of graphene−graphitic carbon nitride composite samples containing Pt as a cocatalyst in methanol aqueous solutions. This study shows that graphene sheets a...
1,660 citations
TL;DR: In this article, the authors describe the polycondensation of this structure, how to modify band positions and band gap by doping and copolymerization, and how to texture the organic solid to make it an effective photocatalyst.
Abstract: Polymeric graphitic carbon nitride (for simplicity, g-C3N4) is a layered material similar to graphene, being composed of only C, N, and some impurity H. Contrary to graphenes, g-C3N4 is a medium band gap semiconductor and an effective photocatalyst for a broad variety of reactions, and it possesses a high thermal and chemical stability In this Perspective, we describe the polycondensation of this structure, how to modify band positions and band gap by doping and copolymerization, and how to texture the organic solid to make it an effective photocatalyst. We then describe the photochemical splitting of water and some mild and selective photooxidation reactions catalyzed by g-C3N4.
1,449 citations
TL;DR: Wang et al. as discussed by the authors proposed a method for the extraction of Colloid Chemistry Max-Planck Institute of Colloids and Interfaces Research Campus Golm, 14476 Potsdam (Germany).
Abstract: [*] Prof. X. C. Wang, X. F. Chen, Prof. X. Z. Fu Research Institute of Photocatalysis State Key Laboratory Breeding Base of Photocatalysis Fuzhou University, Fuzhou 350002 (PR China) E-mail: xcwang@fzu.edu.cn; xzfu@fzu.edu.cn Prof. X. C. Wang, Dr. A. Thomas, Prof. M. Antonietti Department of Colloid Chemistry Max-Planck Institute of Colloids and Interfaces Research Campus Golm, 14476 Potsdam (Germany)
1,122 citations
TL;DR: Isolated single-atom platinum (Pt) embedded in the sub-nanoporosity of 2D g-C3 N4 as a new form of co-catalyst maximizes the atom efficiency and alters the surface trap states of g-N4, leading to significantly enhanced photocatalytic H2 evolution activity.
Abstract: Isolated single-atom platinum (Pt) embedded in the sub-nanoporosity of 2D g-C3 N4 as a new form of co-catalyst is reported. The highly stable single-atom co-catalyst maximizes the atom efficiency and alters the surface trap states of g-C3 N4 , leading to significantly enhanced photocatalytic H2 evolution activity, 8.6 times higher than that of Pt nanoparticles and up to 50 times that for bare g-C3 N4 .
1,061 citations