1. CO2 electrocatalytic conversion: Recycling CO2 to mitigate the greenhouse effect; storing renewable and excess energy to alleviate energy shortages; and producing high-value-added chemicals. 2. Nitrate/nitrite electrocatalytic conversion: Electrocatalytically converting nitrate/nitrite ions in water to produce ammonia, achieving wastewater treatment and green hydrogen storage. 3. Hydrogen production through water electrolysis