Plant mediated biogenic precipitation method for the synthesis of nanomaterial: The possibilities and Challenges

The need for eco-friendly synthesis of nanomaterials has now reached the milestone at  plant mediated Green synthesis or otherwise called biogenic precipitation of nanomaterials. It is a reduction reaction wherein the precursor salt undergo biogenic reduction in presence of a plant extract to zero valent metal or metal oxide nanoparticles. The main advantages of such synthesis techniques lie on its non-toxicity, fast rate of synthesis, in situ mode, less agglomeration among nanoparticles, biocompatibility etc. Of course, the temperature and pH can play a part of their own. In most of the cases, the challenge that prevails over the above said possibilities is the lack of yielding top quality crystals of nanomaterials so synthesised. Some times the samples become totally amorphous soon after the synthesis which need further heating at high temperatures for a long period of time depending on the composition. While the non-crystallanity limits the application of the material, the high temperature heating degrades the biogenic coating over the nanoparticles which in turn bring up further agglomeration among small particles and cut the biocompatibilty of the material. Hence the objective is, we need quality crystals of nanomaterials capped with biogenic compounds soon after the synthesis itself. Heating up to some degree of temperatures for a while can be admitted for the aging of crystals without hampering the biomaterials present. The appropriate use of plant materials as reductant, control over pH and initial concentration of samples are all decisive factors in this ride. To this mess if something new could be added, by virtue it should be an advantage.