PtPd alloy-enhanced cube In2O3 for hydrogen sensing: low detection limits and reduced operating temperatures

With the increasing global demand for clean energy, hydrogen energy will play an increasingly crucial role in future human life, serving as a key driver of the low-carbon economy. Alloy semiconductor nanomaterials exhibit substantial benefits in gas sensing applications due to their distinctive characteristics. This paper reports the synthesis of alloy PtPd-modified cubic In 2 O 3 nanomaterials via a hydrothermal method to optimize their hydrogen (H 2 ) sensor performance. Compared to pure In 2 O 3 and previously reported bimetallic-modified semiconductor hydrogen sensors, the cubic PtPd/In 2 O 3 sensor demonstrates impressive H 2 sensing performance. The 4 at% PtPd/In 2 O 3 (Pt:Pd = 1:1) sensor shows a response value (S = Ra/Rg) of 11.23 to 100 ppm H 2 at 60 °C, with response and recovery times of 73 s and 135 s, respectively. Additionally, the 4 at% PtPd/In 2 O 3 sensor exhibits excellent H 2 selectivity and good repeatability. The chemical state changes of the samples in an H 2 environment were analyzed using in-situ XPS. The enhanced sensor performance is mainly attributed to the synergistic sensitization effect of the PtPd alloy, which reduces the activation energy of gas reactions and increases the content of chemisorbed oxygen. The PtPd/In 2 O 3 sensor shows great potential for low-temperature, low-concentration H 2 detection.