Graphitic carbon nitride (g–C3N4)–based metal-free photocatalysts for water splitting: A review

Recent advances in anion doped g-C3N4 photocatalysts: A review

Recent advances in 3D g-C3N4 composite photocatalysts for photocatalytic water splitting, degradation of pollutants and CO2 reduction

The overwhelming challenge of depleting fossil fuels and anthropogenic carbon emissions has driven research into alternative clean sources of energy. To achieve the goal of a carbon neutral economy, the harvesting of sunlight by using photocatalysts to split water into hydrogen and oxygen is an expedient approach to fulfill the energy demand in a sustainable way along with reducing the emission of greenhouse gases. Even though the past few decades have witnessed intensive research into inorganic semiconductor photocatalysts, their quantum efficiencies for hydrogen production from visible photons remain too low for the large scale deployment of this technology. Visible light absorption and efficient charge separation are two key necessary conditions for achieving the scalable production of hydrogen from water. Two-dimensional carbon based nanoscale materials such as graphene oxide, reduced graphene oxide, carbon nitride, modified 2D carbon frameworks and their composites have emerged as potential photocatalysts due to their astonishing properties such as superior charge transport, tunable energy levels and bandgaps, visible light absorption, high surface area, easy processability, quantum confinement effects, and high photocatalytic quantum yields. The feasibility of structural and chemical modification to optimize visible light absorption and charge separation makes carbonaceous semiconductors promising candidates to convert solar energy into chemical energy. In the present review, we have summarized the recent advances in 2D carbonaceous photocatalysts with respect to physicochemical and photochemical tuning for solar light mediated hydrogen evolution.

Sunlight-driven water-splitting using two-dimensional carbon based semiconductors

Synthesis and fabrication of g-C3N4-based materials and their application in elimination of pollutants

As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has attracted much attention for solving the worldwide energy shortage and environmental pollution. In this work, for the first time we report oxygen self-doping of solvothermally synthesized g-C3N4 nanospheres with tunable electronic band structure via ambient air exposure for unprecedentedly enhanced photocatalytic performance. Various measurements, such as XPS, Mott–Schottky plots, and density functional theory (DFT) calculations reveal that such oxygen doping can tune the intrinsic electronic state and band structure of g-C3N4via the formation of C–O–C bond. Our results show that the oxygen doping content can be controlled by the copolymerization of the precursors. As a consequence, the oxygen doped g-C3N4 shows excellent photocatalytic performance, with an RhB photodegradation rate of 0.249 min−1 and a hydrogen evolution rate of 3174 μmol h−1 g−1, >35 times and ∼4 times higher than that of conventional thermally made pure g-C3N4 (0.007 min−1 and 846 μmol h−1 g−1, respectively) under visible light. Our work introduces a new route for the rational design and fabrication of doping modified g-C3N4 photocatalyst for efficient degradation of organic pollutants and H2 production.

/pdf/oxygen-self-doped-g-c3n4-with-tunable-electronic-band-2lpqhb9g1x.pdf

Oxygen self-doped g-C3N4 with tunable electronic band structure for unprecedentedly enhanced photocatalytic performance.

The invention discloses a method for preparing a Mn2O3 porous micro-nano structure material having controllable morphology. The method comprises that ammonium bicarbonate and manganese acetate as raw materials in water as a solvent undergo a reaction under control of concentrations of the two raw materials, a mixing rate and reaction time to produce manganese carbonate precursors having different main body morphologies, and the manganese carbonate precursors are sintered at a high temperature to form a Mn2O3 porous negative electrode material having a controllable main body structure. The Mn2O3 material microstructure can be controlled and changed from a porous ball to a porous cube and has the sizes of 1-1.5 microns and mesoporous sizes of 10-30nm. The method has the advantages of common and nontoxic raw materials, simple and easy reaction, high conversion rate, large yield, industrial production feasibility and excellent performances in the field of sodium ion batteries.

Method for preparing Mn2O3 porous micro-nano structure material having controllable morphology

The invention discloses a method for in-situ synthesis of a g-C N /Cuo composite material. The method comprises the following steps of 1) uniformly stirring acetonitrile and an organic solvent to obtain a mixed reaction solvent; 2) stirring and dissolving dicyandiamide and copper nitrate into the mixed reaction solvent obtained in the step 1) to obtain a precursor solution; and 3) heating the precursor solution to perform a solvent thermal reaction, and then performing separating, purifying and drying to obtain the g-C N /Cuo composite material. The preparation method is simple, the reaction conditions are mild, and the procedure is simple; and the prepared g-C N /Cuo composite material has lithium storage performance with high circulation stability and high electrode specific capacity, and can be used as a negative electrode material of a lithium ion battery.

Method for in-situ synthesis of graphite phase carbon nitride-copper oxide composite material

The invention discloses a network-like hierarchical pore structured Mn2O3/C composite material. By uniformly coating Mn2O3 with a carbon layer, the composite material is prepared. The composite material shows a continuous three-dimensional network-like hierarchical pore structure including macropores and micropores. Pore diameter of the macropores is 20-30 nm, and pore diameter of the micropores is 2-5 nm. Mn2O3 belongs to a cubic system, Ia-3 space group. The preparation method of the network-like hierarchical pore structured Mn2O3/C composite material comprises the following step: trioctylamine used as a solvent and anhydrous manganese acetate used as a manganese source are heated in the atmosphere of nitrogen protection to carry out a thermal reaction so as to obtain tan MnO precipitate, and the precipitate is placed in the air atmosphere and calcined to obtain the final product. The raw materials in the invention are common and nontoxic, and have high conversion rate and high yield. In addition, the reaction is simple and feasible. The invention has a good prospect in the field of energy storage.

Network-like hierarchical pore structured Mn2O3/C composite material and preparation method thereof

The invention discloses a molybdenum disulfide quantum dot/copper-indium-sulfur composite photocatalyst for generating hydrogen from visible light. The composite photocatalyst is prepared by loading MoS2 quantum dots serving as a co-catalyst on a curd like CuInS2. According to the photocatalyst disclosed by the invention, by loading the MoS2 quantum dots on a curd like CuInS2 base material, the problems in photoelectron-hole combination and photocorrosion in a CuInS2 composite material can be inhibited to a certain degree, the photoabsorption efficiency and the photocatalytic hydrogen generation efficiency of the obtained composite material are effectively improved, the application range of the composite material is widened, and the problem that existing sulfide-based photocatalytic raw material often employs an expensive precious metal as a co-catalyst so as to improve the catalyst performance; the preparation method has the advantages of simplicity, wide source of raw materials and low cost and adaptability to popularization and application.

Molybdenum disulfide quantum dot/copper-indium-sulfur composite photocatalyst for generating hydrogen from visible light and preparation method of molybdenum disulfide quantum dot/copper-indium-sulfur composite photocatalyst

Wei Fangyan

Papers

Oxygen self-doped g-C3N4 with tunable electronic band structure for unprecedentedly enhanced photocatalytic performance.

Method for preparing Mn2O3 porous micro-nano structure material having controllable morphology

Method for in-situ synthesis of graphite phase carbon nitride-copper oxide composite material

Network-like hierarchical pore structured Mn2O3/C composite material and preparation method thereof

Molybdenum disulfide quantum dot/copper-indium-sulfur composite photocatalyst for generating hydrogen from visible light and preparation method of molybdenum disulfide quantum dot/copper-indium-sulfur composite photocatalyst