Enhanced colorimetric detection of hydrogen using PdO-decorated ZnO covered with a metal-organic framework membrane

Safety concerns dictate the need for an affordable method of detecting the leakage of hydrogen. Simple colorimetric hydrogen sensors may provide a solution for achieving such detection. Herein, we report significant enhancements in eye-readable hydrogen detection via the formation of a metal-organic framework membrane on the surface of a hydrogen-responsive pigment. As a model system, PdO-decorated ZnO covered with a zeolitic imidazolate framework-8 (PdO/ZnO@ZIF-8) is synthesized and verified through material characterizations. When compared to a bare PdO/ZnO sensor, a colorimetric hydrogen sensor fabricated from PdO/ZnO@ZIF-8 yields a remarkably shortened response time, a moderate increase in detection sensitivity, and a significant enhance-ment in selectivity against potential interferents. These improvements are interpreted with the molecular sieving effect, electronic modulation of active centers, and acceler-ated sorption kinetics of hydrogen. The outstanding pigment is utilized to prepare a hydrogen detection tape that demonstrates a great potential in naked-eye detection of a hydrogen leak.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.