Simple fabrication of morphology-tunable Ag2S and Ag architectures assisted by denatured bovine serum albumin

In this work, denatured bovine serum albumin (dBSA) is used as a structure-directing agent to fabricate Ag microplates, Ag2S nanochains and raspberry-like nanostructures. By simply adjusting the pH of a dBSA–Ag+ mixture, Ag2S nanochains and raspberry-like nanostructures are obtained at pH 8 and 10, respectively. The structure-directing function of dBSA in different aggregated forms at different pH is discussed. Ag microplates are produced from Ag2S precursor without additional reductants at pH 5. A formation mechanism of Ag microplates is proposed that involves three steps: Ag2S nanoparticle formation, Ag seed formation, and Ag crystal growth. Ag2S nanoparticles function as a source-host and provide S2− ions that reduce excess Ag+ ions.