Infrared Spectra Patterns of Coconut Shell Charcoal as Result of Pyrolysis and Acid Activation Origin of Sulawesi, IndonesiaMeytij Jeanne Rampe, Ignatius R. S. Santoso, Henny Lieke Rampe, Vistarani Arini Tiwow and Anastasya ApitaE3S Web Conf., 328 (2021) 08008DOI: https://doi.org/10.1051/e3sconf/202132808008