Apparatuses and methods for synthesizing nanoscale materials are provided, including semiconductor nanowires. Precursor solutions include mixed reagent precursor solutions of metal and chalcogenide precursors and a catalyst, where such solutions are liquid at room temperature. The precursor solutions are mixed by dividing a solution flow into multiple paths and converging the paths to form a uniform solution. A thermally controlled reactor receives the uniform solution to form semiconductor nanowires. Various electronic, optical, and sensory devices may employ the semiconductor nanowires described herein, for example.