Template-Assisted Synthesis of Hierarchical Gas Sensing Materials: From Structural Design to Performance Optimization

Gas-sensing technology is indispensable in fields such as environmental monitoring, industrial safety, food quality control, and medical diagnostics. Template-assisted synthesis can be employed to construct hierarchical structures in gas-sensing materials, enabling precise multiscale control over morphology, porosity, and intrinsic electronic properties, thereby paving the way for developing next-generation gas sensors with enhanced sensitivity and selectivity. Continuous innovations in the synthesis of hierarchical materials like metal oxide semiconductors (MOS) and metal-organic frameworks (MOFs) have significantly enhanced gas sensing performance in stability, response speed, sensitivity, and selectivity. However, a systematic analysis linking hierarchical structures built via different templating methods to sensing performance remains lacking. This review systematically summarizes the design principles, control mechanisms, and functional applications of three primary templating approaches. Furthermore, this work examines how tailored templating strategies can balance structural precision, synthetic complexity, and environmental impact. Finally, we offer forward-looking perspectives on future development pathways, as well as the challenges and opportunities for practical applications.