Surface oxygen vacancy defect engineering of p-CuAlO2via Ar&H2 plasma treatment for enhancing VOCs sensing performances

The as-synthesized CuAlO2 particles were then coated onto a thin alumina substrate with micro-interdigital electrodes; the local temperature of the sensing layer (the thickness is about 15 mm; see the cross-sectional image in Fig. S1, ESI) was programmed using a Pt microheater.9 After the aging of CuAlO2 sensors at 350 1C, surface VO defects were tailored by Ar&H2 plasma treatment for 30, 60 and 90 min, respectively.

The CuAlO2 sensors herein are referred to as pristine, PT-30, PT-60 and PT-90 sensors. Their VOCs response properties were examined in a SD101 sensing system (Hua Chuang Rui Ke Technology Co., Ltd); additional details on sensor fabrication and measuring conditions are provided in the ESI.The present plasma treatment (30–60 min) doesn’t cause any detectable impurity phases (examined by fine XRD scan shown in Fig. S2, ESI), and noticeable variations of surface morphology/ roughness (SEM images in Fig. S2, ESI).