Alkali‐Driven Assembly of Protein‐Rich Biomass Boosts the Electrocatalytic Activity of the Derived Carbon Materials for Oxygen Reduction

Abstract

Though of great significance, it is still a challenge to facilely engineer biomass into heteroatom-doped porous carbon materials (HPCs)-based electrocatalysts with high activity and durability to replace Pt-based ones for oxygen reduction reaction (ORR). Herein, alkali-driven assembly strategy is proposed to boost the ORR catalytic performance of the HPCs derived from protein-rich biomass. Egg white for instance, can self-assemble into a hydrogel with 3D networks in the presence of alkali. The formed hydrogel can work as a self-heteroatom (N, S) doped and self-activated precursor for fabricating HPCs. The as-obtained NSPC-1-900 ORR catalyst has onset potential (E onset ) and half-wave potential (E 1/2 ) values of 1.03 and 0.88 V (vs. RHE) respectively, and it represents an air electrode catalyst for Zn-air batteries with high power density and durability. This work affords a facile and effective strategy of utilizing low-cost, abundant and sustainable biomass to prepare HPCs for energy storage and conversion.HClO 4 was obtained from Sigma-Aldrich. All reagents were of analytical grade and used without further purification. 20 % Pt/C commercial catalyst (Johnson-Matthey HiSPEC 3000) was used for comparison. Nafion solution (5 wt%) was obtained from Sigma-Aldrich. Fresh eggs were purchased from local supermarket. 4 5 6 7 8

Co,N-Codoped Porous Carbon-Supported CoyZnS with Superior Activity for Nitroarene Hydrogenation

“…This difference further confirms the successful embedding of Co into ZnS, which can interact with Zn to affect the Co electronic structure. , Compared with Co@NPC XPS, peaks for CoN x -Co y ZnS@NPC-Z at 779.7 eV (Co 3+ ) and 783.6 eV (Co 2+ ) show a slight shift (Figure c), verifying the interaction between Zn and Co in the phase of Co 0.025 Zn 0.975 S. − The peak at 780.3 eV is a characteristic profile for Co–N x . The high-resolution XPS spectrum of S 2p is deconvoluted into two peaks at the binding energy of 162.7 and 167.9 eV (Figure d), corresponding to coordinated S, and oxidized sulfur species, respectively. , The C 1s spectra display the peaks, standing for CC, C–O/CN, and C–O–C/C–N species (Figure S1c in the Supporting Information). − The N 1s spectra are deconvoluted into four subpeaks, representing pyridinic-N (397.5 eV), pyrrolic-N (398.4 eV), graphitic-N (400.1 eV), and oxidized N (402.6 eV) (Figure S1d in the Supporting Information). ,, As reported previously, the pyridinic-N can coordinate with Co to form stable Co–N x . , The N-doped carbon can improve the conductivity of carbon, in favor of the catalytic activity of CoN x -Co y ZnS@NPC- Z (Figure S1d). The XPS results are in good agreement with the XRD results of the CoN x -Co y ZnS@NPC- Z samples, verifying the existence of CoN x and Co 0.025 Zn 0.975 S.…”

Non‐N‐Doped Carbons as Metal‐Free Electrocatalysts

“…Even so, we summarize the best performance for various reactions catalyzed by different heteroatoms‐doped carbons in Figure for easy comparison. [ 118–158 ] As can be seen, N‐doped carbon catalysts show better catalytic performance over other heteroatom‐doped carbons for ORR and water splitting. For non‐N‐doping, only B‐doping has been reported for ORR, P‐doping for OER, and F‐doping for HER to show catalytic performance comparable to the N‐doping.…”

Recent Advancements in the Synthesis and Application of Carbon-Based Catalysts in the ORR

“…These materials displayed a more positive onset potential compared to the Pt/C catalyst and superior stability over 10,000 cycles (4 mV shift). Xu et al [79] utilized biomass (egg whites) hydrogels which formed 3D networks under alkaline conditions as a framework for N and S co-doped carbons. Alkaline conditions are also commonly used in pyrolysis to generate porous structures in activated carbons.…”