Copper compounds have important functions and applications in many fields. The following are some major copper compounds and their functions: 1. Pesticides and fungicides Copper oxides: such as copper oxides and copper hydroxide, are often used in agriculture as fungicides and insecticides, and can effectively control a variety of plant diseases (such as downy mildew, red leaf disease, etc.). 2. Catalysts Copper catalysts: Copper-phosphorus alloys, copper nanoparticles, etc. are often used in catalytic reactions in organic synthesis, especially in gas synthesis, hydrogenation reactions, etc. 3. Industrial applications Copper salts: such as copper sulfate, copper chloride, etc. are widely used in industrial processes such as electroplating, leather making, dyes and chemical synthesis. 4. Material science alloys: Copper and its alloys (such as brass, bronze) are widely used in the manufacture of mechanical parts, building materials, electronic components, etc.