Characterization of functional groups and crystal structure of activated carbon from ketapang fruit biomass using FTIR and XRD Alifah Naira Soraya ; Iwan Nugraha Gusniar ; Nidya Chitraningrum ; Irma Apriyani ; Hana Arisesa ; Ahmad Fudholi Komunikasi Fisika Indonesia 8 Sep 2026 10.31258/jkfi.23.1.53-58
