Enhanced hydrogen gas sensing using palladium - graphene oxide (PdGO) thin films

Hydrogen is a sustainable carbon-free energy, very much needed for future power generation to mitigate NetZero mission. To realise the power of hydrogen energy, safety sensors for hydrogen leak detection are of utmost importance from production to consumption. Palladium (Pd), known to absorb 900 times hydrogen as compared to its own volume at room temperature and 1 atm pressure, plays a key role in storage and sensing. However, the major drawback of Pd is the incomplete desorption of hydrogen from its lattice. To overcome this limitation, in this work, Pd is modified with graphene oxide (GO) to enhance its hydrogen absorption-desorption characteristics. PdGO thin films were deposited on SiO2/Si substrates (1x1 cm(2)) using spin coating. The synthesised PdGO thin films were characterised using XRD, FTIR, XPS, FESEM, EDS, TEM and SAED techniques. The films were tested for H-2 gas sensing by varying parameters such as concentration of GO, temperature, and hydrogen gas concentration. Highest response of 32.2 % at 100 ppm of H-2 exposure and 150 degrees C is obtained for PdGO-200 (with 200 mg GO). Improvement in recovery time by a factor of > 10 as compared to the PdGO sensor reported in literature, is achieved. PdGO-200 also demonstrated high selectivity for hydrogen among other gases (NO2, H2S, CO, and NH3). These results pave the way for future improvements in gas sensing technology and open up new possibilities for reliable H-2 sensor that can significantly improve industrial safety.