Open Access

ARTICLE

Synergistic Effect of Low-Concentration ZnCl₂-Activated Bio-Carbon from Red Suren Leaves with Hierarchical Pore Structure and Self-Doping for High-Performance Supercapacitor Applications

Erman Taer^1,*, Novi Yanti¹, Asmarwati¹, Apriwandi¹, Abrar Ismardi², Indra Wahyudhin Fathona², Memoria Rosi², Bidayatul Armynah³, Dahlang Tahir³, Ninis Hadi Haryanti⁴, Suryajaya⁴, Isnasyauqiah⁵, Ida Usman⁶, Julnaidi⁷, Rika Taslim^8,*

1 Department of Physics, University of Riau, Simpang Baru, Indonesia
2 Department of Engineering Physics, School of Electrical Engineering, Telkom University, Bandung, Indonesia
3 Department of Physics, Hasanuddin University, Makassar, Indonesia
4 Department of Physics, University of Lambung Mangkurat, Banjarmasin, Indonesia
5 Department of Chemical Engineering, University of Lambung Mangkurat, Banjarmasin, Indonesia
6 Department of Physics, Haluoleo University, Kendari, Indonesia
7 Department of Mechanical Engineering, Sekolah Tinggi Teknologi Pekanbaru, Pekanbaru, Indonesia
8 Department of Industrial Engineering, Universitas Islam Negeri Sultan Syarif Kasim Riau, Simpang Baru, Indonesia

* Corresponding Authors: Erman Taer. Email: ; Rika Taslim. Email:

(This article belongs to the Special Issue: Renewable Nanostructured Porous Materials: Synthesis, Processing, and Applications)

Journal of Renewable Materials 2026, 14(8), 4 https://doi.org/10.32604/jrm.2026.02026-0022

Received 11 February 2026; Accepted 08 June 2026; Issue published 26 August 2026

Abstract

The promotion of bio-carbon for developing superior electrodes has become a trending topic in realising the practical application of supercapacitor devices. This study aimed to prepare porous carbon (PC) with a taproot fiber-like nanostructure that was decorated with self-doped oxygen. The waste of red suren leaves (RSL) was further treated using a direct heating method with the catalyst effect of ZnCl₂ (0.3, 0.5, and 0.7 M) in an N₂/CO₂ environment at 850°C, being examined. The results showed that RSL@PC-0.5 exhibited the best amorphous carbon structure (FWHM = 0.105° and 0.182°). The specific surface area (SSA = 495.31 m²/g) and the combination of hierarchical nanostructure with abundant multi-level pores (micro-mesopores) were supported by the appropriate presence of O (4.26%) heteroatoms. Oxygen within the carbon matrix enhanced the electrode-electrolyte interaction by adding active sites, thereby contributing additional pseudocapacitance. Furthermore, the electrochemical performance showed a high specific capacitance of 490 F/g at a current density of 1 A/g. The energy density and power density reached 62.93 Wh/kg and 156.67 W/kg, indicating the excellent electrochemical performance of the RSL@PC-0.5 material. This study presented a supercapacitor material derived from biomass, showing a new PC with O self-doped fiber nanostructures that could serve as a rational reference for the practical application of environmentally friendly energy storage.

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