Insights into Gas-Exfoliation and the In-Situ Template Mechanism of Zinc Compound for Lignin-Derived Supercapacitive Porous Carbon

Abstract

The large-scale production of porous activated carbon is plagued by the overuse of corrosive activators, so developing a green and mild activation strategy is technologically urgent and meaningful. Herein, two gentle activators (ZnCO 3 and ZnC 2 O 4 ) and a traditional corrosive agent (ZnCl 2 ) are utilized to activate lignin for porous carbons, and the microstructures and electrochemical properties of the carbons are systematically investigated. By tracking the evolution of the carbonized products through TG-MS, in-situ FT-IR, and other characterization methods, the gas-exfoliation and in-situ template functions of ZnCO 3 and ZnC 2 O 4 are proposed. It was found that the pyrolysis synergistic effect between ZnC 2 O 4 and lignin boosts the decomposition of oxygen-containing groups, playing a pivotal role in the fabrication of hierarchical porous carbon with crumpled nanosheets. The electrochemical properties of the carbons are closely correlated to their porous structures. Benefiting from the well-developed crumpled lamellar units, the hierarchical porous carbon activated by ZnC 2 O 4 has a high specific surface area and good conductivity. Consequently, it exhibits a higher capacitance than the microporous carbon activated by ZnCl 2 and the mesoporous carbon activated by ZnCO 3 .

Lignin‐derived carbon materials for catalysis and electrochemical energy storage

“…Therefore, tremendous efforts have been made to develop green and efficient technologies for the production of PLCs. [ 66–69 ]…”

“…Meanwhile, the symmetric supercapacitor assembled with this carbon electrode exhibited high energy densities of 11.84 and 66.18 Wh kg −1 in 6 M KOH and ionic liquid electrolytes, respectively (Figure 8c). Yang et al [ 67 ] proposed an in‐situ gas exfoliation and template method to prepare PLC with high mesoporosity. It was found that ZnCO 3 and ZnC 2 O 4 have dual functions of activation and template.…”

“…Therefore, tremendous efforts have been made to develop green and efficient technologies for the production of PLCs. [66][67][68][69] Zhang et al's [66] work proposed a green bacterial activation to synthesize PLC (Figure 8a). It revealed that bacteria can break the β-O-4′, β-β′, and β−5′ bonds of lignin molecules, which beneficial to form an interconnected hierarchical porous carbon structure and promoting graphitization.…”

On-Line Thermally Induced Evolved Gas Analysis: An Update—Part 1: EGA-MS

“…By tracking the evolution of the carbonized products through mass spectrometry, in situ FTIR, and other characterization methods, the gas-exfoliation and in situ template functions of zinc carbonate and zinc oxalate were proposed by Fu and coworkers, who found that the pyrolysis synergistic effect boosts the decomposition of oxygen-containing groups, playing a pivotal role in the fabrication of hierarchical porous carbon with crumpled nanosheets [ 144 ].…”

Lignin derived carbon materials: current status and future trends

“…Owing to gas exfoliation and in-situ ZnO template roles of ZnC 2 O 4 during the carbonization process, porous LDPC quasi-nanosheets with a SSA of 1069 m 2 g −1 and a total pore volume of 1.375 cm 3 g −1 were obtained(Fu et al 2020). Furthermore, Fu et al investigated the effects of ZnCO 3 and ZnC 2 O 4 on the structure of LDPC, and concluded that ZnC 2 O 4 had a synergistic effect with lignin, playing a key role in the preparation of hierarchical porous carbon with crumpled nanosheets(Fu et al 2021).…”