Do not know whether this approach found wider application or just a solution proposed after evaluating it.
Obviously it is based on differences on redox potential. The less noble metal goes into solution when contacted with the more noble metal ion. Working with nanoparticles will provide higher surface area, however, I would assume for a practical application iron wool or iron slag would be much more economical.
Zerovalent Iron (ZVI) can be easily changed in H2O to nano-structured Fe2+ or Fe3+, eventually nano-structured Fe(OH)2 or Fe(OH)3 or FeOOH, which have extremely high sorption capacities for a number of heavy metals including Pb2+.