Supported metal nanomaterials have great potential in catalytic sensing, but the poor selectivity and easy aggregation of noble metals limit their development in non-enzyme sensing applications. Herein, this research focuses on the metal-support interactions of Pd supported on PCN-222, exploring the role of abundant porphyrin groups on the PCN-222 surface and the tuning of Pd composition to enhance electron configuration. Through the anchoring of PCN-222 surface to Pd species and utilizing the confining effect of open channels, the Pd@PCN-222 nanostructures with uniform particle size of Pd were successfully obtained. Strong electron interaction can enhance the catalytic activity of Pd@PCN-222 towards reaction, while increasing the Pd loading can improves the sensitivity of the sensors in the high concentration of H2O2. Combining the above two points, 0.29 %-Pd@PCN-222 exhibits a low detection limit of 0.27 μM and a wide linear range of 1–1000 μM in H2O2 sensing via using a colorimetric method. Experimental and theoretical results show that Pd@PCN-222 exhibit strong p-d orbital coupling and adsorption, and rapid catalytic kinetics towards H2O2, enhancing the overall catalytic process. At the same time, DFT calculations are used to simulate the material surface and sensing process, which also enrich the research content of MOF materials in sensing. From the structure-performance relationships to the directly analyze the H2O2 in real samples, this work is expected to provide some guidance for the development of efficient sensing systems.
Read full abstract