One-step synthesis of nanocarbon-decorated MnO2 with superior activity for indoor formaldehyde removal at room temperature

Indoor formaldehyde (HCHO) pollution receives wide concerns, it is still a challenge to remove low-level HCHO at high gas-hourly space velocity (GHSV) at room temperature required in the indoor environment. Thus, a graphite-like nanocarbon decorated MnO2 (GLC-MnO2) was synthesized with a rapid one-step procedure, i.e., a redox reaction between potassium manganese and glucose at 80 degrees C for 15 min. The as-synthesized GLC-MnO2 hybrid showed excellent activity for HCHO removal and its mineralization to CO2 at room temperature. Under the GHSV of 600 L/g(cat) h, the single-pass removal efficiency was as high as similar to 92% for 0.5 mg/m(3) HCHO and similar to 89% for 1.0 mg/m(3) HCHO, which is much higher than those previously achieved by MnO2-based catalysts. Furthermore, its room-temperature activity was little influenced by the relative humidity in the wide range of 4%-80%. The significantly enhanced catalytic performance of GLC-MnO2 could be attributed to abundant Mn vacancies and surface adsorbed active oxygen resulted from the coexisted nanocarbon which in-situ formed during preparation of GLC-MnO2. The presence of nanocarbon may also facilitate electron transfer to form reactive oxidation species for HCHO oxidation. The present study provides a new route to develop efficient catalyst for indoor air pollutants removal.