Controllable synthesis of 3D PdCu/Ti3C2Tx hierarchical nanostructures for chemiresistive room temperature H2 sensors

To enhance the detection performance of hydrogen (H 2 ), we employed a self-sacrificing template method to prepare a three-dimensional (3D) PdCu-modified Ti 3 C 2 T x nanocomposite , denoted as PdCu/Ti 3 C 2 T x . Within 3D PdCu/Ti 3 C 2 T x nanocomposite, PdCu as the active center component, was evenly distributed on Ti 3 C 2 T x nanosheets . The unique architecture increased the exposure of active center sites, while the Ti 3 C 2 T x nanosheets provided additional gas diffusion channels, thereby contributing to improved gas sensing performance. Comparing to PdCu nanoparticles , PdCu/Ti 3 C 2 T x exhibited an enhancing response and a fast response time of 4 s to 0.5 % H 2 . PdCu/Ti 3 C 2 T x also showed an ultra-low detection limit of 0.1 % H 2 and excellent repeatability, selectivity and long-term stability. The outstanding gas sensing performance could be attributed to the 3D structure and the heterostructure between PdCu and Ti 3 C 2 T x . The insights gained from this study provide novel perspectives for designing and synthesizing high-performance gas-sensitive materials.