A water purification electrode composed of a porous carbon material is disclosed. The electrode may be used as a flow-through cathode in an electro-peroxone process providing high H2O2 production activity for electrochemical wastewater treatment. The porous carbon material is a binding agent-free carbon structure that enables H2O2 to be electro-generated in situ at cathode. The porous carbon material may be synthesized from resorcinol and can provide a relatively large reaction surface area of 200-800 m2/g. The porous carbon material also achieves low energy consumption as well as a wide pH working range, making it suitable for treating many types of organic, inorganic, and biological contaminants in water. The electrode may be integrated with an anode, ozone generator, and other components into a compact, integrated water purification system.