Sandwich-structured composite from the direct coassembly of layered titanate nanosheets and Mn porphyrin and its electrocatalytic performance for nitrite oxidation

• Mn porphyrin has been inserted into the interlayer of layered titanate by an ESD method.
• MnTMPyP cations were found to be tilted about 42° against the titanate nanosheets.
• MnTMPyP–Ti4O9 hybrid shows good electrocatalytic activity toward nitrite oxidation.

MnTMPyP–Ti4O9 nanocomposite was prepared by the direct coassembly of oppositely charged building blocks, exfoliated titanate nanosheets and 5,10,15,20-tetrakis(N-methylpyridinium-4-yl) porphyrinato manganese(III), MnTMPyP cations. XRD, IR, SEM, and TEM revealed that Mn porphyrin has been successfully inserted into the lamellar spacing of layered titanate. The metalloporphyrin molecules incorporated within the nanocomposite were found to be tilted approximately 42° against the titanate nanosheets. Further, the obtained MnTMPyP–Ti4O9 nanocomposite has been examined for the electrochemical detection of nitrite using cyclic voltammetry and differential pulse voltammetry techniques. The electrochemical studies demonstrated that MnTMPyP–Ti4O9 nanocomposite detects nitrite linearly over a concentration range of 2.0×10−6–1.57×10−3 M with the detection limit of 1.25×10−6 M at a signal-to-noise ratio of 3.