This paper presented the plasmonic Bi in-situ deposited on the surface of Bi2O2CO3 nanoplates forming plasma enhanced Bi/Bi2O2CO3 heterojunction photocatalyst through a facile one-pot solvothermal method by using methanol as both solvent and carbon source. The water splitting efficiency of the as-prepared Bi/Bi(2)O(2)CO(3 )heterojunction photocatalyst was much better than that of pure phase Bi2O2CO3 due to the Bi nanoparticles surface plasma resonance (SPR) effect for promoting light response and the charge carriers separation and transfer. The experimental results also showed that the H2O played an important role in the fabrication of Bi/Bi(2)O(2)CO(3 )heterojunction photocatalyst, furthermore, the content of Bi in Bi/Bi2O2CO3 changed with the variation of additional H2O which impacted photocatalytic activities. The method of semimetal in-situ deposition without reductants in this work also provided new perspectives into the rational design and facile synthesis of bismuth based semiconductor photocatalysts. (C) 2020 Elsevier Inc. All rights reserved.