Porous Boron Carbon Nitride Nanosheets as Efficient Metal-Free Catalysts for the Oxygen Reduction Reaction in Both Alkaline and Acidic Solutions

Abstract

Carbon materials have become a hot topic as potential substitutes for Pt/C catalysts for the oxygen reduction reaction (ORR). However, most of them exhibit their catalytic activities only in alkaline solutions, which severely limits their application in polyelectrolyte membrane fuel cells. To address this issue, here porous boron carbon nitride (BCN) nanosheets are fabricated by a facile and efficient polymer sol−gel method, which involves the annealing of polyvinylic akohol (PVA), boric acid, guanidine, and poly(ethylene oxide-co-propylene oxide) (P123) gel mixtures. The as-prepared porous BCN nanosheets possess a high surface area of 817 m 2 /g and display impressive ORR catalytic performance in both alkaline and acidic media, rivalling that of commercial Pt/C and other recently reported carbon materials. Importantly, the resulting metal-free catalysts exhibit much greater durability and higher methanol tolerance in both alkaline and acidic environments. This study provides a new insight into metal-free ORR catalysts that are practicable in industrial fuel cells.

Carbon Nitride/Reduced Graphene Oxide Film with Enhanced Electron Diffusion Length: An Efficient Photo‐Electrochemical Cell for Hydrogen Generation

“…[6,7] Despite significant progress in this field, [3,[10][11][12][13][14][15][16][17] semiconductors that fulfill all these requirements rarely exist today, and the production of such semiconductors is still much sought after.Over the past few years, polymeric graphitic carbon nitride (CN) has attracted widespread attention due to its outstanding electronic properties, which have been exploited in various applications, including photo-and electrocatalysis, [18][19][20][21][22][23][24] heterogeneous catalysis, [25][26][27][28] CO 2 reduction, [29][30][31] water splitting, [32][33][34][35][36][37][38][39][40] light-emitting diodes, [41] photovoltaics, [42][43][44] and sensing. [6,7] Despite significant progress in this field, [3,[10][11][12][13][14]…”

“…Over the past few years, polymeric graphitic carbon nitride (CN) has attracted widespread attention due to its outstanding electronic properties, which have been exploited in various applications, including photo-and electrocatalysis, [18][19][20][21][22][23][24] heterogeneous catalysis, [25][26][27][28] CO 2 reduction, [29][30][31] water splitting, [32][33][34][35][36][37][38][39][40] light-emitting diodes, [41] photovoltaics, [42][43][44] and sensing. [45][46][47] Its unique and tunable optical, chemical, and catalytic properties, alongside its low price and remarkably high stability to oxidation, make it a very attractive material for PEC applications.…”

Layered Boron–Nitrogen–Carbon–Oxygen Materials with Tunable Composition as Lithium‐Ion Battery Anodes

“…7, 192.7, and 193.9 eV,c orresponding to BÀN, [25] BNÀC, [14] andb orate, [26] respectively.T hese peaks are presenti n other BNPyr samples as well ( Figure S7 in the Supporting Information). The C1ss pectra of all BNPyr (Figure 2b and Figure S7 in the Supporting Information) reveal similar existences of sp 2carbon,C ÀN/CÀO, and C=Oa tb inding energies of 284.6-284.9, [27] 286.1-286.4, [12] and 287.3-287.8 eV, [28] respectively.W e could observe only an egligible amount ( Figure S7 in the Sup- porting Information) of CÀBs pecies in BNPyr 500 because this bond formation is less favorable energetically.T his strengthens the assumption that boron binding occurs mainly through nitrogen and oxygen atoms. The C1ss pectra of all BNPyr (Figure 2b and Figure S7 in the Supporting Information) reveal similar existences of sp 2carbon,C ÀN/CÀO, and C=Oa tb inding energies of 284.6-284.9, [27] 286.1-286.4, [12] and 287.3-287.8 eV, [28] respectively.W e could observe only an egligible amount ( Figure S7 in the Sup- porting Information) of CÀBs pecies in BNPyr 500 because this bond formation is less favorable energetically.T his strengthens the assumption that boron binding occurs mainly through nitrogen and oxygen atoms.…”

“…Traditional BNCO synthetic methodsi nclude solid-state reactions, [9] chemical vapor deposition (CVD), [10] and organic addition reactions of BN to polycyclic aromatic hydrocarbons (PAHs). The CVD methodo ffers low scalability,w hereas the solid-state reactionp rovides moderate control over the composition and positionofheteroatoms within the carbon network and usually includes templating, [12] externalm edia, [13] and condensation of different solid powders. The CVD methodo ffers low scalability,w hereas the solid-state reactionp rovides moderate control over the composition and positionofheteroatoms within the carbon network and usually includes templating, [12] externalm edia, [13] and condensation of different solid powders.…”

Improving the gas barrier, mechanical and thermal properties of poly(vinyl alcohol) with molybdenum disulfide nanosheets

“…The degree of enhancement depends strongly on the polymer–nanofiller interactions in the interphase regions. 2D nanosheets such as graphene, hexagonal boron nitride, montmorillonite, borocarbonitrides, and transition metal dichalcogenides have been investigated to characterize their unique characteristics . Molybdenum disulfide (MoS 2 ) nanosheets, as transition metal dichalcogenides, have the transition metal layer (molybdenum atomic layer) sandwiched between two chalcogenide atomic layers (sulfur atoms).…”