Purification and variable frequency system and method

An air cleaning apparatus comprising an ion generation electrode, a collecting electrode, and a support portion,

• wherein:
• the ion generation electrode is configured to apply a high-voltage to thereby form a high-voltage electric field between the collecting electrode and the ion generation electrode;
• a passage is formed between the ion generation electrode and the collecting electrode along a direction of the high-voltage electric field;
• the support portion supports at edges of the ion generation electrode and the collecting electrode, and is configured to provide electrical isolation and mechanical support for the ion generation electrode and the collecting electrode;
• a surface of the support portion between the ion generation electrode and the collecting electrode comprises a surface coating layer with a property of resisting ion bombardment and accidental arcing;
• wherein the support portion has an arc-shaped concave portion facing an ion movement trajectory, or the surface of the support portion is disposed away from an ion bombardment region.