Hydrothermal Carbonization of Walnut Shell Biomass to Biochar for Supercapacitor Application. Indian Journal of Pure & Applied Physics (IJPAP), [S. l.], v. 61, n. 8, p. 692–696, 2023. DOI: 10.56042/ijpap.v61i8.351. Disponível em: https://or.niscpr.res.in/index.php/IJPAP/article/view/351. Acesso em: 18 jul. 2026.