A novel formaldehyde sensor based on the pseudocapacitive catalysis of birnessite

A novel electrochemical sensor for the detection of formaldehyde with high sensitivity and good selectivity was fabricated, which is composed of a low cost and environmentally benign MnO2 film, and not of noble metals or biological components. The MnO2 film was grown on a glassy carbon electrode from aqueous KMnO4 solution via a cathodic mechanism, possessing low crystalline birnessite structure and pseudocapacitive characteristics.

► A novel electrochemical sensor for formaldehyde has been proposed.
► The sensor is composed of MnO2 film grown cathodically from KMnO4.
► The electrode is not accompanied by poisoning, allowing the repetitive use.