The synthesis of Na4Sn2S6•14H2O was carried out according to previous reports. To a 100 mL glass bottle, Na2S•9H2O (14.4 g, 60 mmol) and 90 mL DI H2O were added and stirred for 5 hr to form a clear solution. To a 50 mL centrifuge tube, SnCl4•5H2O (7.0 g, 20 mmol) and 5 mL DI H2O were added and stirred for 5 hr to form a clear solution. The SnCl4 solution was then added dropwise (using a separatory funnel) into the Na2S solution while stirring. The resulting crude Na4Sn2S6 solution was then stirred overnight. The crude solution was then added dropwise to 300 mL acetone in a 500 mL glass bottle under vigorous stirring. A yellowish-white precipitate is formed during this process. After the addition, the suspension is placed in the freezer for 5 hr. At the same time, 100 mL of neat acetone in a separate glass bottle is also chilled in the freezer for 5 hr. At this point, the chilled suspension is decanted and the solid is shaken together with 100 mL of chilled acetone. The suspension is decanted again and the solid is dried in a vacuum oven at room temperature overnight to give an off-white pale precipitate (5.53 g, 72% yield).