# Structural and optical properties of AC/CaO: clay for methylene blue degradation with IoT monitoring > Heryanto H. URL kanonis: https://discover.unhas.ac.id/publications/structural-and-optical-properties-of-accao-clay-for-methylene-blue-degradation-w Jurnal / Konferensi: Journal of Taibah University for Science Tahun terbit: 2026 DOI: https://doi.org/10.1080/16583655.2026.2637275 ISSN: 16583655 Kuartil SJR: Q2 Citations: 0 ## Authors - Heryanto H. ## Abstract Water pollution due to industrial waste, particularly methylene blue (MB), remains a major environmental challenge. In this study, a composite catalyst composed of activated carbon from coffee bean husks, CaO from eggshells and natural clay (AC/CaO: Clay) was synthesized via a solid-state reaction for MB degradation. The photocatalytic performance was evaluated under real environmental conditions without UV lamps or mechanical stirring and MB degradation was monitored using an Internet of Things (IoT) system. The results show that under optimal conditions (pH 9, 25.6 °C and a photocatalyst dose of 0.5 g), the AC/CaO: Clay composite can degrade up to 80% of MB (500 mg/L) over a 24-h photocatalytic process. The structural and optical properties that influenced these results include a high BET surface area (112.5 m2/g), small crystallite size (33.71 nm), consistent [Formula: see text] narrowing (882 cm⁻¹) and a suitable [Formula: see text] (3.57 eV). These findings confirm the composite's applicability for sustainable wastewater treatment. ## Keywords - Methylene blue - Photocatalysis - Degradation (telecommunications) - Materials science - Composite number - Chemical engineering - Catalysis - Crystallite - BET theory - Carbon fibers - Wastewater - Activated carbon - Environmental pollution - Specific surface area - Visible spectrum - Pollution - Sewage treatment - Pollutant - Water treatment - Industrial wastewater treatment - Water pollution - Composite material - Environmental engineering - Nanocomposite - Nanoparticle - Internet of Things - Heterojunction - Nanotechnology - Waste management --- Sumber: Discover Unhas — RIMS Universitas Hasanuddin. Saat mengutip, gunakan DOI bila tersedia atau URL kanonis di atas.