One-step nanocasting synthesis of crystalline mesoporous CoO without using reducing agent

• It is a one-step nanocasting synthesis for mesoporous metal oxide with low oxidation status.
• No reducing agent is used during the synthesis.
• The obtained products possess highly ordered mesostructure with crystalline frameworks.

Ordered mesoporous crystalline CoO material was synthesized by a simple one-step nanocasting synthesis method using mesoporous silica as a hard template and cobalt nitrate Co(NO3)2·6H2O as the metal precursor. The cobalt nitrate precursor was impregnated inside the mesopore space of the hard template and was in-situ converted to Co3O4 in the first stage. Then it was further converted to CoO by directly heating up the intermediate to 740–780 °C for 2 h in an tube furnace under a constant nitrogen gas flow. No hydrogen or organic reducing agent was used. The obtained mesoporous CoO possesses ordered mesostructure and crystalline framework. This method provides a new facile and green strategy for the synthesis of mesoporous metal oxides with lower oxidation states.