Ammonium dithiotungstate (NH₄) ₂WO₂S₂ is an important thiometallic ammonium salt. After thermal decomposition, transition metal chalcogenide tungsten disulfide WS₂ can be obtained. It can be used in the synthesis of tungsten iron sulfur cluster compounds, semiconductors, superconductors, photoelectrochemical solar cells, hydrogen storage materials and electrode materials. It has good application and is the precursor of coal liquefaction and heavy oil hydrogenation catalysts. It can also be used as raw materials for the preparation of supported and non-supported tungsten sulfide hydrogenation catalysts. Therefore, it is of great significance to develop a high yield method for the preparation of high purity ammonium dithiotungstate.

Structural ceramics have maintained a strong and sustained growth in the past few years. This growth in demand stems not only from the growth of many different applications, but also from the exploration and attention of people to the science of ceramic materials. As demand continues to grow, people need stronger, more durable, lighter, and more heat-resistant materials to accomplish more impossible tasks. Material manufacturers must seek new innovative processes to produce the next generation of ceramics.

Recently, the United States is looking around for alternatives to China's rare earths. In addition, a hurricane hit the US state of Florida, causing damage to almost half of the F-22 aircraft in the base. It seems that the "Eagle Eye" filmed by NASA is not only "eyelid" and "eyes", but the power is also sufficient. Worse, these fighters are "invisible", so that the current count of damage is still in progress. Up to now, there are more than 20 damaged points. According to military experts, is this loss worth hundreds or even thousands of Lamborghini? It seems that this loss is a bit big. So, now, it is estimated that the F-22 production line is waiting for the rare earth to “open the pot”.

The hexagonal tungsten oxide has attracted much attention because its single crystal has an empty hexagonal space tunnel structure. W in the compound exists in the mixed valence states of W₆⁺, W₅⁺ and W₄⁺, thus making the charge balance of the compound as a whole. This unique spatial structure and special valence state make it have good optical effect.