Characterization of porous cubic silicon carbide deposited with Pd and Pt nanoparticles as a hydrogen sensor

Porous 3C-SiC (pSiC) samples with different pore diameters were prepared from polycrystalline n-type 3C-SiC films by electrochemical anodization using a mixture of HF and ethanol as the electrolyte solution. The pSiC surface was chemically modified via the sputtering of Pd and Pt nanoparticles as a hydrogen catalyst. Changes in the resistance were monitored with respect to hydrogen concentrations in the range of 110–410 ppm. The variations in the electrical resistance at the presence of nitrogen diluted with hydrogen demonstrated that Pd and Pt-deposited pSiC samples have the ability to detect hydrogen. Regardless of the catalyst, the 25 nm pore diameter samples exhibited better response and recovery properties than the 60 nm pore diameter samples. It was found that the pore size affects the catalyst reaction and results in changes in the response factor to hydrogen. A large change in resistivity was observed with the Pd catalyst and the hydrogen sensing performance improved at high temperatures.