Cu_(2)O/MnCo_(2)O_(4)异质结纳米光催化剂还原CO _(2)的研究

REDUCTION OF CO _(2) BY Cu _(2)O/MnCo _(2)O_(4) HETEROJUNCTION NANO-PHOTOCATALYST

Z型异质结光催化剂具有导带和价带电荷分离能力强、氧化还原能力强等优点,被光催化研究者所青睐。采用水热法制备了Z型Cu_(2)O/MnCo_(2)O_(4)异质结纳米光催化剂,并对其物理化学性质进行了详细表征,评价了其光催化CO_(2)还原性能。结果表明:Cu_(2)O/MnCo_(2)O_(4)异质结纳米光催化剂相比MnCo_(2)O_(4)纳米颗粒,改善了可见光吸收性能,降低了带隙,有效延缓了电子-空穴对的复合,降低了电子-空穴对转移运动电阻,从而提高了催化剂的光催化活性;15%(w)Cu_(2)O含量的异质结纳米光催化剂具有最优的光催化CO_(2)还原性能,CO产率为98.6μmol g,CH 4产率为68.4μmol g,重复使用6次后其催化活性基本无变化。

Z-type heterojunction photocatalyst was favored by researchers because of strong charge separation ability of conduction band and valence band,and strong oxidation-reduction ability.Z-type Cu_(2)O/MnCo_(2)O_(4)heterojunction nano-photocatalysts were prepared by hydrothermal method,their physical and chemical properties were characterized in detail,and their photocatalytic CO_(2)reduction performance was evaluated.The characteristic results of XRD,HRTEM,UV vis,PL and EIS showed that compared with MnCo_(2)O_(4)nano-particles,Cu_(2)O/MnCo_(2)O_(4)heterojunction nano-photocatalyst could improve the visible light absorption performance,reduce the band gap,delay the recombination of electron-hole pairs effectively,and reduce the transfer resistance of electron-hole pairs,which confirmed that heterojunction nano-structures could effectively improve the photocatalytic activity for CO_(2).The evaluation results of photocatalytic reduction of CO_(2)showed that heterojunction nano-photocatalyst with 15%(w)Cu_(2)O content had the best photocatalytic activity for CO_(2)reduction,and the CO yield was 98.6μmol g,the yield of CH_(4) was 68.4μmol g,and its catalytic activity remained unchanged after 6 times of recycling uses.