Constructing Successive Active Sites for Metal‐free Electrocatalyst with Boosted Electrocatalytic Activities Toward Hydrogen Evolution and Oxygen Reduction Reactions

Abstract

As well known, heteroatom doped carbon material served as metal‐free electrocatalyst for hydrogen evolution (HER) and oxygen reduction reactions (ORR) particularly relies on the heteroatom doping level. Here, we report a 3D porous nitrogen doped carbon (PNC) electrocatalyst with superior HER and ORR electrocatalytic activities derived from the calcination of the discarded cigarette butt and dicyandiamide possessing a high nitrogen content (20 at%). PNC electrocatalyst only demands 143 mV versus RHE to achieve 10 mA cm−2 ascribed to the high nitrogen percentile in PNC electrocatalyst favorable for constructing successive active centers contributing to efficiently catalyzing HER. Ignorable degradation in HER activity observed after 10000 potential cycles as well as undetectable decay in HER performance recorded after 12 h operation indicate high stability of PNC electrocatalyst. Meanwhile, half‐wave potential of PNC electrocatalyst reaches 0.81 V versus RHE in 1 M KOH electrolyte. Additionally, stable ORR activity attained after 1000 potential cycles is indicative of high stability. A comparably high zinc‐air battery performance with maximum power density of 66 mW cm−2 is achieved by PNC electrocatalyst. This study highlights the importance of nitrogen doping level in metal‐free electrocatalyst for boosting HER and ORR activities.

3D Carbon Materials for Efficient Oxygen and Hydrogen Electrocatalysis

“…Zhang et al produced a 3D N‐doped carbon through the calcination of discarded cigarette butts as a carbon source and dicyandiamide as a N source. The resultant electrocatalyst possessed 20% N and required 143 mV (vs RHE) to achieve 10 mA cm −2 in HER, performance comparable to that of Pt/C.…”

Tungsten Carbide Hollow Microspheres with Robust and Stable Electrocatalytic Activity toward Hydrogen Evolution Reaction

“…For large-scale industrial commercialization of water-splitting, development in an efficient and cost-effective HER electrocatalyst as a substitution of Pt electrocatalyst is of paramount desirability. 4−7 Intensive attention has been paid to transitional-metal sulfides, 1,8,9 carbides, 10−12 nitrides, 13−15 phosphides, 16−21 oxides, 22−25 and selenides 26,27 because the strong interaction between the transition metal and H* could be loosened after the incorporation of the above-mentioned elements, resulting in a neither too strong nor too weak interaction between the electrocatalyst with H* triggering efficient hydrogen evolution. 28…”

One Simple Strategy towards Nitrogen and Oxygen Codoped Carbon Nanotube for Efficient Electrocatalytic Oxygen Reduction and Evolution

“…Green and sustainable energy sources play a crucial role in addressing concerns about the global energy dilemma, pollution, and climate change [1][2][3]. Regenerative energy techniques involving fuel cells, metal-air batteries, and electrocatalytic hydrogen production have attracted significant interest as energy storage and conversion devices [4,5], which usually involve cathodic oxygen reduction reaction (ORR) and anodic oxygen evolution reaction (OER). Both ORR and OER contain complicated multi-electron transfer processes, which would result in sluggish reaction kinetics and consequently compromise the whole performance of the above energy devices.…”

“…The noble metal-based materials including Pt and Ru are the most efficient electrocatalysts for ORR or OER, but their prohibitive cost and scarcity greatly impedes the proliferation of related energy technologies. In comparison, carbon materials possess a series of satisfactory features, including natural abundance, superior electrical conductivity, tailorable structures and components, and strong anticorrosion abilities, and thus have been intensively studied as electrocatalysts during the last decade [5,8,9].…”

“…Recently, we have exploited polydopamine (PDA) as an excellent platform for doped carbons due to its unrivaled structural and componential virtues [17,19]. Robust adhesion can make PDA easily grow onto the surfaces of different solids and thus realize structural regulation [5,20]. Simultaneously, the flexible componential tunability by the post-modification of PDA facilitates the importation of multiple kinds of heteroatoms to the derived carbons [17].…”