Abstract:
Global warming is the biggest threat to the entire world owing to the continuous release of greenhouse gases such as CO2 from various sources. Herein, we have utilized renewable energy for the conversion of CO2 to valuable feedstocks through a semiconductor-mediated photocatalytic system. The cadmium sulfide nanoflowers (CS-NFs) decorated graphitic carbon nitride (CN) through a solvothermal route to form a Z-scheme CSCN heterojunction. The as-synthesized material has been characterized by various spectroscopic and microscopic tools. The optimal CSCN-0.5 (1:0.5) photocatalyst achieves a CO production rate of 130.9 μmol g-1 under visible light irradiation of 4h (λ > 420 nm), doubling that of pristine CS-NFs and CN. CO, along with CH4 (3.4 μmol g-1) and C2H6 (2.9 μmol g-1), is the sole product detected. Experimental results indicate that the CSCN-0.5 photocatalyst spatially separates electron-hole pairs, suppresses charge carrier recombination, and maintains robust redox ability, enhancing CO2 photoreduction. The CO2 reduction mechanism over CSCN heterojunction was also studied through in-situ DRIFTS and electron spin resonance (ESR) measurements. Therefore, CSCN proves that it could be used as a robust photocatalyst for the CO2 reduction reactions towards C1 and C2 feedstocks.
摘要:
由于各种来源的二氧化碳等温室气体的持续释放,全球变暖是对整个世界的最大威胁。在这里,我们利用可再生能源通过半导体介导的光催化系统将CO2转化为有价值的原料。硫化镉纳米花(CS-NFs)通过溶剂热途径修饰石墨氮化碳(CN),形成Z方案CSCN异质结。合成后的材料已通过各种光谱和微观工具进行了表征。最佳CSCN-0.5(1:0.5)光催化剂在4h(λ>420nm)的可见光照射下实现了130.9μmolg-1的CO产生速率,原始CS-NFs和CN的两倍。CO,连同CH4(3.4μmolg-1)和C2H6(2.9μmolg-1),是检测到的唯一产品。实验结果表明,CSCN-0.5光催化剂在空间上分离电子-空穴对,抑制电荷载流子复合,并保持强大的氧化还原能力,增强CO2光还原。还通过原位DRIFTS和电子自旋共振(ESR)测量研究了CSCN异质结上的CO2还原机理。因此,CSCN证明其可以用作针对C1和C2原料的CO2还原反应的稳健光催化剂。