In one aspect, the present disclosure pertains to methods of making various noble metal nanoprisms, e.g., gold nanoprisms. In various aspects, the methods can comprise incubating, under dark conditions, a growth solution comprising: (a) a plurality of gold seed structures; (b) a gold precursor, and (c) a photocatalytic intermediary, such that during the incubating step multiply-twinned gold seed structures in the growth solution are preferentially enlarged. The disclosed methods can comprise separating the multiply-twinned gold seed structures from the growth solution based upon the size of the gold seed structures to produce an enriched growth solution. In some aspects, the methods comprise irradiating the enriched growth solution to produce the gold nanoprisms. In some aspects, the disclosed nanoprisms comprise silver.