Metal-organic frameworks derived curled sheet-like Cu2O/CuO heterostructure: Low-power N2H4 sensing

[Display omitted] •Using simple MOFs-template method to synthesize Cu2O/CuO composite.•The Cu2O/CuO sensor exhibits excellent N2H4 sensing performance at 40 °C.•The p-p heterojunction promotes the effective separation of electrons and holes.•The Cu2O/CuO composite has more surface adsorbed oxygen content.•This work realizes the first detection of N2H4 gas using CuO based sensor. From the perspective of ensuring human health and industrial production safety, there is an urgent need for sensitive and effective detection of the highly toxic compound hydrazine (N2H4). In this work, precursor was used as self-template, and the curled sheet-like Cu2O/CuO composite was prepared by sintering treatment. Compared with pure CuO, the formation of p-p heterojunction in Cu2O/CuO composite promotes the transfer of charge carrier, resulting in more surface adsorbed oxygen and better N2H4 sensing performance. At 40 °C, the response of Cu2O/CuO sensor to 100 ppm N2H4 is 15.1, which is 1.9 times of that of pure CuO. The response/recovery time of the Cu2O/CuO sensor is 50 s/490 s, the minimum detection limit is 30 ppb, and has good selectivity and long-term stability (6 weeks). In addition, we investigated the sensing mechanism of N2H4 gas through X-ray photoelectron spectroscopy (XPS) and Gas chromatography-mass spectrometry (GC–MS) techniques. This study is the first time to achieve the detection of N2H4 gas using CuO based sensor.