A novel conjugated microporous poly(benzothiadiazole)-Bi2MoO6 (BBT-BMO) Z-scheme heterojunction was fabricated in situ through a facile palladium-catalyzed Sonogashira-Hagihara cross-coupling poly condensation of 4,7-dibromobenzo[c][1,2,5]thiadiazole and 1,3,5-triethynylbenzene on the surface of Bi2MoO6. Characterization results illuminated that BBT was stably coated on the surface of Bi2MoO6 nanosheets with the formation of C-O bonds. This novel BBT-BMO composite exhibited superior photo catalytic performance in both sulfathiazole degradation and Cr(VI) reduction compared with pure BBT and Bi2MoO6 in visible light. In line with systematic characterizations results, a reasonable photocatalytic mechanism based on direct Z-scheme heterojunction was proposed and further verified via (OH)-O-center dot determination. This Z-scheme heterojunction endowed it with improved visible light absorption, larger surface area, and greater electron-hole separation and thus efficiently enhanced the photocatalytic performance. This work provides new insight into the utilization of conjugated microporous polymers in photocatalysis and paves a new way to construct Z-scheme heterojunctions with enhanced photocatalytic performance via metal-free polymers modification. (C) 2016 Elsevier Inc. All rights reserved.