NOVELTY - Synthesizing a doped carbon composite, comprises: (a) preparing a solution having a material containing tannin and an additive containing a doping chemical element, or (a1) preparing a solution having a carbon source material and a heteroatom containing additive; (b) evaporating the solution to yield many powders; and (c) subjecting the powders to a heat treatment for a duration of time to produce the doped carbon composite.    USE - The method is useful for synthesizing doped carbon composite, which is useful: for visible light degradation of organic molecules in water; in an article of manufacture such as supercapacitor, fuel cell, photovoltaic cell, lithium ion battery, air filter or water filter (all claimed); for enhanced decomposition of organic molecules (fats, oils, polychlorinated biphenyls, explosives, dyes and organic toxic runoffs); in food and bio-medical industries as antibacterial, antiviral and antifungals; in air purification systems to kill microbes, volatile organic compounds, formaldehyde, ammonia, cigarette fumes, automobile and industrial exhausts; in water purification systems; for destruction of chemical warfare agents; for hydrogen production by splitting water; in self-cleaning surfaces including odor absorbing and odor destroying properties; and for destruction of ethylene gas for prolonging the life of fruits.    ADVANTAGE - The method: utilizes inexpensive, readily available and renewable resource materials as carbon source, hence it is economical; is quick and reproducible; does not require any gases from outside source during the synthesis; and provides the doped carbon composite that has high visible light absorption high stability, increased conductivity and interesting optical properties, and is easy to produce.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for a composite synthesized either by pyrolysis of a mixture of tannin and melamine, where the synthesis process comprises (a2) dissolving the tannin and the melamine in water to form a homogeneous solution, and the steps (b) and (c) as above per se, or by the steps (a1), (b) and (c) as above per se.