On January 3, 2023, Beijing time, Professor Qiao Shizhang’s team from the University of Adelaide in Australia published a research result entitled “A General Approach to 3D Printed Single Atom Catalysts” in the journal Nature Synthesis.
By developing a new type of natural polymer as a precursor, the result realizes the combination of 3D printing strategy and single-atom materials, and the synthesis strategy shows good versatility in the synthesis of single-atom materials. The corresponding author of the paper is Professor Qiao Shizhang of the University of Adelaide.
Single-atom catalysts (SACs) are isolated metal atoms anchored to a solid matrix, which has the advantages of high atomic economy and adjustable coordination environment. At present, the general synthesis strategy of single atoms based on chemical methods is highly dependent on expensive precursors or complex loaded substrates, which significantly increases the overall cost of large-scale manufacturing of single atoms. In addition to chemical synthesis, general-purpose synthesis strategies based on mechanical wear, thermal shock or laser irradiation often require special equipment. Therefore, it is still a great challenge to develop a simple and economical general synthesis strategy to synthesize single-atom catalysts on a large scale.
3D printing technology, also known as additive manufacturing technology. 3D printing technology can assemble the target material directly, thus avoiding the complex wet chemical processes in the synthesis steps described above. On the other hand, the wide application of 3D printing technology in many aspects has brought a large number of cheap 3D printers and 3D printing ink materials, which significantly reduces the cost of large-scale production. Finally, 3D printing technology can also efficiently and automatically construct materials at multiple scales from microns to meters, bringing opportunities for the industrial production of specific materials.
Recently, Professor Qiao Shizhang’s team at the University of Adelaide in Australia has developed a new single-atom general synthesis strategy. This synthesis strategy uses natural polymer gelatin, which is common in daily life, as a precursor to synthesis, and creatively realizes the combination of 3D printing strategy and single-atom materials.
Figure 1: 3D printing synthesis and characterization of typical samples.
Figure 2: The commonality of this synthesis strategy in terms of elemental and atomic loads.
This synthesis strategy shows good versatility, and the synthesis of a variety of monatomic materials is realized through the change of synthesis method. By changing the formula of the printing ink, the amount of elements in the monoatomic material and the atomic load is adjusted. Synchronization radiation X-ray absorption spectroscopy and high-resolution spherical aberration electron microscopy both demonstrate that the regulation of elements and concentrations does not affect the dispersion of atoms in the resulting material.
Figure 3: Commonality of this synthesis strategy in coordination environments and different printing modes.
The characterization results show that even if the transition metal precursor in the precursor is changed or the natural polymer is used as the substrate material, the resulting material is still a monatomic material. At the same time, the coordination environment of the obtained monatomic material can be regulated by changing the precursor and using post-treatment methods. Finally, the characterization results show that the use of different 3D printing parameters does not affect the dispersion of atoms in the final material.
Figure 4: Performance verification of 3D printed single-atom catalyst electrodes.
Finally, the authors used nitrate reduction to verify the electrocatalytic performance of the obtained electrode. Compared with carbon-based electrodes without monoatoms, electrodes loaded with iron monatoms exhibit higher electrocatalytic performance, proving that the 3D printing process does not affect the electrochemical performance of single-atom catalysts. At the same time, the characterization results after the test prove that the dispersion of atoms in the obtained material is still retained after the test, which proves that it has good stability.
This study reports a novel synthesis strategy for single-atom materials, and the combination of 3D printing strategy and single-atom materials gives continuous production capacity and multi-scale scalability during the production of single-atom materials. This synthesis strategy provides a potential way for large-scale production or continuous production of single-atom materials, which brings potential opportunities for the subsequent large-scale industrial production and application of single-atom materials.
The research work has received help and support from the Institute of Physics of the Chinese Academy of Sciences, the University of Otago in New Zealand, the First Affiliated Hospital of Dalian Medical University, the First Affiliated Hospital of Zhengzhou University and the Australian Synchrotron Radiation Center. (Source: Science Network)
Related paper information:https://doi.org/10.1038/s44160-022-00193-3