Optimizing the Micro/Mesoporous Structure of Hierarchical Porous Carbon Synthesized from Petroleum Pitch Using the Solvent-Free Method for Ultra-Fast Capacitive Deionization

Guan-Wen Liu; Chen-Shiuan Fan; Chun-Han Hsu; Chia-Hung Hou; Hong-Ping Lin

doi:10.1021/acsomega.2c04119

Optimizing the Micro/Mesoporous Structure of Hierarchical Porous Carbon Synthesized from Petroleum Pitch Using the Solvent-Free Method for Ultra-Fast Capacitive Deionization

ACS Omega. 2022 Dec 15;7(51):47610-47618. doi: 10.1021/acsomega.2c04119. eCollection 2022 Dec 27.

Authors

Guan-Wen Liu¹, Chen-Shiuan Fan², Chun-Han Hsu³, Chia-Hung Hou², Hong-Ping Lin¹

Affiliations

¹ Department of Chemistry, National Cheng Kung University, No.1, University Road, Tainan701, Taiwan.
² Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei106, Taiwan.
³ General Education Center, Nation Tainan Junior College of Nursing, No. 78, Sec 2, Minzu Rd., Tainan700, Taiwan.

Abstract

In this work, a solvent-free ZnO-template method is used to synthesize hierarchical porous carbons (denoted as HPC-X; X = 1, 1.5, 2, and 4 g of ZnO) via the pyrolysis of petroleum industrial-residual pitch with ZnO. The proposed method allows precise control of the micro/meso/macroporous structure of the HPC by adjusting the amount of ZnO. The results show that the average pore size of HPCs prominently increases from 2.4 to 3.7 nm with the increase in the ZnO/pitch ratio. In addition, it is shown that HPCs have a high surface area between 1141 and 1469 m² g^-1, a wide-range pore size distribution (micro-, meso-, and macropores), and a tap density ranging from 0.2 to 0.57 g cm^-3. The capacitive deionization performances of HPCs for sodium and chloride ions are investigated. The results show that HPC-2 exhibits the highest electrosorption capacity of 9.94 mg g^-1 within 10.0 min and a maximum electrosorption capacity of 10.62 mg g^-1 at 1.2 V in a 5.0 mM NaCl solution. Hence, HPC-2 is a highly promising candidate as an electrode material for rapid deionization.