Cultivating titanium dioxide nanoarrays on gas diffusion layer for advancing self-humidifying proton exchange membrane fuel cell

Ensuring consistent and reliable operation of proton exchange membrane fuel cells (PEMFCs) in low humidity environments is crucial for their real -world application. In this study, we introduce an innovative approach to address this challenge by employing a uniform growth of single crystal rutile titanium dioxide nanoarray (TiO2NRs) on the gas diffusion layer (GDL) through a seed coating hydrothermal method, which leads to the creation of a novel self-humidifying membrane electrode assembly (MEA). The effects of TiO2NRs on the wettability, resistance, performance and stability of the MEA were investigated, and the loading capacity was optimized. The results reveal that the integration of TiO2NRs into the MEA offers superior performance under 21 % relative humidity (RH) conditions compared to conventional doping TiO2 nanoparticles into the catalyst layer (CL). By optimizing the TiO2NRs loading to 0.32 mg cm -2 of the MEA, a remarkable peak power density of 689.36 mW cm -2 was achieved at low humidity, equivalent to 93 % of the performance observed at 100 % RH. In addition, a 24 -hour continuous test at constant voltage (0.6 V) showcased the exceptional stability of the TiO2NRs-based MEA, which is attributed to the unique water retention capabilities of the TiO2NRs within the CL, facilitating enhanced regulation of water balance within the PEMFC.