Graphitic carbon nitride (g-C3N4) as a metal-free candidate of photocatalyst has received worldwide attention because of its greatpotentials in solarlight-induced degradationand hydrogen evolution,yet the industrial application is seriously hindered by the small specific surface area and rapid recombination rate of carriers. Herein, we demonstrate that porous g-C3N4 (HCl-CNU-X) can be prepared via the co-polymerization of acidified melamine and a green bubble template (urea). Transmission electron microscopy and nitrogen sorption characterization results show that the prepared HCl-CNU-X possesses an in-plane porous structure and large specific surface area, enabling the exposure of more accessible active sites. As a result, HCl-CNU-X exhibits both enhanced photocatalytic tetracycline hydrochloride degradation and higher hydrogen evolution than bulk g-C3N4. The boosted photocatalytic performance was ascribed to the formation of the porous structure, which dramatically promotes the separation of charge-carriers and facilitates the electron transfer. This work demonstrates that the acidification of nitrogen-rich precursors combined with a bubble-template can develop a new paradigm of highly porous photocatalysts for environmental remediation and water splitting.