Biorecovery of platinum group metals to nanoparticles: Current status, prospects, and challenges

Abstract

With the penetration of automobiles, spent automobile catalysts are the major secondary source of Platinum group metals. Spent automotive catalyst has higher quantities of platinum group metals than natural ores. Recovering platinum group metals from spent automotive catalysts has the potential to yield significant economic and environmental benefits. Conventional recycling techniques necessitate the use of several chemical reagents or the deployment of high-tech equipment and significant energy consumption, which inevitably results in the generation of toxic and harmful substances. However, biorecovery processes are regarded as viable options for Platinum group metals recovery. The substantial ability of microorganisms to bioreduce metal ions may obtain metal nanoparticles of varying morphologies and sizes through the action of various enzymes (reductase, hydrogenase) and proteins. This review summarizes the current process of biosynthesis of Platinum group metal nanoparticles, as well as potential synthesis mechanisms. Meanwhile, the specific applications of microbial sourced nanoparticles in medicine, catalytic environmental pollutants, and biosensors are discussed, and the future development of microbial nanomaterials synthesis has been further prospected.