Microstructural and Carbon Phase Analysis of Water Hyacinth Derived Biochar under Particle Size Variation

Water hyacinth is an abundant lignocellulosic biomass with strong potential as a sustainable carbon source. This study aims to investigate the effect of particle size variation on the carbon phase and microstructural development of biomass-derived carbon from water hyacinth. The leaves of water hyacinth were used as a raw material, thoroughly washed, cut into small pieces, and sun-dried for 11 days until completely dry. The dried leaves were then ground into powder and sieved into three particle-size fractions of 60, 80, and 100 mesh, with 75 g prepared for each sample. Carbonization was conducted using a furnace at 900°C for 1 h under a limited-oxygen environment. Carbon phase characterization was performed using X-ray diffraction (XRD), while surface microstructure analysis was carried out using Scanning Electron Microscopy (SEM). The results indicate that all samples exhibit a stable amorphous carbon phase, suggesting that particle size variation does not significantly influence carbon phase formation. However, particle size plays an important role in microstructural evolution, where finer particles promote more homogeneous morphology and enhanced pore development. These findings demonstrate that particle size acts as a microstructural control parameter without altering the resulting carbon phase, and they confirm the potential of water hyacinth leaves as a promising biomass precursor for carbon-based materials.