*3.3. IF-WS2 Synthesis by Different Methods*

## 3.3.1. Synthesis of IF-WS2 Nanoparticles from Mixed WO3 and S Powder with H2

Two typical types of experiment were carried out to synthesize the IF-WS2, starting from mixed WO3 and S powder with H2 (experiments S1 and S2). In experiment S1, around 6 g WO3 and S composite powder at a molar ratio of 1:10 was placed into the inlet area. Ar gas was used to purge the quartz tube at 50 mL/min for 30 min, after the system was properly assembled and sealed. The working tube started rotating from 600 °C, at which point H2 (80 mL/min) and Ar (30 mL/min) gases were also introduced. The reaction at 800 °C lasted for 1 h. Similarly, experiment S2 was carried out by adopting a continuous S feeding system.
