Research on the oxygen reduction reaction (ORR) mechanism of g‐C₃N₄ doped by Ag based on first‐principles calculations

Abstract

Developing non‐platinum composite catalysts has become a hot research topic for the oxygen reduction reaction (ORR). In this study, Ag/g‐C3N4 (the mass ratio of Ag and g‐C3N4 = 3%) catalysts were prepared through a photoreduction method. The catalytic performance of g‐C3N4 was greatly enhanced after Ag doping. The current density of Ag/g‐C3N4 was −21 μA/mm2, which is 3 times that of pure g‐C3N4. The mechanism of ORR activity enhancement is discussed based on first‐principles calculation. Ag, as the active site, can reduce the reaction barrier and enhance ORR activity. Combining experimental and computational results forms the subject of this study.

ompg-C3N4/SO3H organocatalyst-mediated green synthesis of 1,2-dihydro-1-arylnaphtho[1,2-e][1,3] oxazin-3-ones under solvent-free and mild conditions: a fast and facile one-pot three-component approach

“…For evaluation of the solvent effect, the model reaction was investigated by applying various solvents (including EtOH, H 2 O, MeOH, CH 3 CN, toluene) and in solvent-free conditions (Table 1, entries [8][9][10][11][12].The results revealed that, in the presence of both types of protic and aprotic solvents, only a trace amount of product was obtained and the best result was achieved in the absence of solvent. In continuance, the influence of temperature was investigated (Table 1, entries [13][14][15][16][17]. Relying on the obtained results, as the temperature was conducted to 100 °C, the desired product was formed at a shorter reaction time and the yield increased to 87% (Table 1, entry 17).…”

“…Generally, g-C 3 N 4 substructure, based on aromatic C-N heterocycles and optimized van der Waals forces between its two-dimensional conjugated planes, can be prepared by polymerization of affordable nitrogen-containing materials like melamine, urea, cyanamide, thiourea, and dicyandiamide [6]. Reasonable physical and chemical property, unique electronic property, exclusive thermal and chemical resistance, and high specific surface area [7] make this material be applied in many scientific fields such as fuel cell [8], sensor [9], solar cell [10], metal-free catalyst [11], heterogeneous photocatalyst [12], energy storage [13], oxygen reduction reaction (ORR) [14], hydrogen evolution [15], photocatalytic degradation of pollutants [16,17], and oxidation [18]. The preparation of wellordered mesoporous g-C 3 N 4 leads to higher specific surface area, stronger adsorption capacity, and larger pore volume and increases active chemical sites, thereby enhancing the performance of g-C 3 N 4 as an efficient catalyst and catalyst support [19,20].…”

One‐Pot Preparation of Binary Photocatalyst ZnO/g‐C3N4 Nanosheets with Enhanced Photocatalytic Activity in Dye Degradation

“…At the same time, g-C 3 N 4 is a kind of effectively modified material semiconductor photocatalysts, many strategies had been proposed to promote the photocatalytic performance of g-C 3 N 4 such as doping with metal elements (K, Na, Fe, Ag, Au, Cu, In, Bi, Mn, Co, etc. ), [19][20][21][22][23][24] free-metal elements (C, P, S, Si, O, etc. ), [25][26][27] metal oxide (ZnO, TiO 2 , Fe 2 O 3 , CuO, Bi 2 O 3 , CeO 2 , WO 3 , Ag 2 O etc.)…”

Theoretical study of activation of O2 at cathode and CH3OH at anode of “CH3OH ‐O2” fuel cell using ZnC4H4 and CuC4H4 organometallic catalysts “a DFT study”

“…Finally, combined fuel cells, known as fuel piles, have wide applications in a variety of fields, such as space crafts, reconnaissance drones, discovery submarines, hybrid cars, and fuel pile power plants. [3][4][5][6][7][8][9] In contrast with these advantages, the major problem with fuel cells is that the cell's reaction rate is typically low and virtually useless under normal conditions. Thus, since the introduction of fuel cells, many researchers, including Denaley et al, have tried to find the effective ways to enhance the fuel cells' reaction rate.…”