A facile soft template method to synthesize hollow carbon and MnO composite particles for effective methylene blue degradation.

Hollow carbon and MnO composite particles (HC-Mn) were fabricated by using polyacrylic acid (PAA) and Mn ion co-assembled colloids as the soft template and resorcinol formaldehyde resin (RF) as the carbon source. The formation process was well studied and a plausible formation mechanism was proposed. The Mn ions played two key roles in the synthesis: first, they promoted the aggregation of the PAA molecules, thus forming the PAA-Mn colloids in solution with high water content, which were suitable for the subsequent RF coating. Secondly, considerable Mn ions were retained after template removal, which were transformed into MnO particles simultaneously during carbonization. This approach was facile and effective and the as-prepared HC-Mn showed superior catalytic activity toward methylene blue (MB) degradation.