Enhanced visible light driven photoelectrocatalytic oxidation of ethanol at reduced graphene oxide/CdS nanowires decorated with Pt nanoparticles
Enhanced visible light driven photoelectrocatalytic oxidation of ethanol at reduced graphene oxide/CdS nanowires decorated with Pt nanoparticles
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DOI：
10.1039/c5cy01693b
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发表时间：
2016-05
影响因子：
5
通讯作者：
A. Arabzadeh;A. Salimi;Maysam Ashrafi;S. Soltanian;P. Servati
中科院分区：
文献类型：
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作者：
A. Arabzadeh;A. Salimi;Maysam Ashrafi;S. Soltanian;P. Servati
在这项研究中，我们报道了一种新型三元杂化物的制备，该三元杂化物由还原氧化石墨烯/CdS纳米线（rGO/CdS NWs/Pt NPs）装饰而成，作为碱性介质中高效的电催化和光催化乙醇氧化平台。首先采用溶剂热法制备了直径为35 nm、长度可达几微米的均匀尺寸的CdS NWs，然后采用简单的水热法以肼为还原剂将Pt NPs修饰的CdS NWs组装到还原氧化石墨烯薄片上。通过各种表征技术，包括场发射扫描电镜（FESEM）、透射电镜（TEM）、能量色散x射线能谱（EDX）、x射线衍射（XRD）、x射线光电子能谱（XPS）、紫外可见光谱和光致发光光谱（PL），获得了所制备的纳米复合材料的形貌、结构和性能数据。利用循环伏安法（CV）和安培法评估电催化活性表明，与CdS NWs、rGO/CdS NWs、CdS NWs/Pt NPs和rGO/Pt NPs等不同组分的纳米结构相比，rGO/CdS NWs/Pt NPs在碱性溶液中表现出更强的电催化活性，且具有更负的起电位。此外，使用低功率LED作为可见光照明源的实验表明，所提出的纳米杂化物对乙醇氧化的电催化活性显著增加，同时与黑暗条件下的- 0.870 V相比，Ag/AgCl的起始电位向- 0.950 V的负电位转移。这种高电催化和光催化性能可归因于CdS NWs与还原氧化石墨烯的最大界面接触，这减少了纳米结构的团聚并抑制了光生电子-空穴复合。此外，在还原氧化石墨烯的存在下，加速了电子转移，并通过在CdS NWs上均匀沉积Pt NPs获得了更大的比表面积，这有助于提高催化活性。这项研究为一维半导体-还原氧化石墨烯/铂三元杂化物的合成提供了一种简单的策略，并有望将其作为一种高效的可见光催化剂应用于不同的化学转化和能量转换装置。
In this study, we report the preparation of a novel ternary hybrid consisting of reduced graphene oxide/CdS nanowires decorated with Pt nanoparticles (rGO/CdS NWs/Pt NPs) as an efficient electrocatalytic and photoelectrocatalytic ethanol oxidation platform in alkaline medium. The synthesis was accomplished by a solvothermal method in the first step to prepare uniformly sized CdS NWs with diameters of 35 nm and lengths up to several micrometers, followed by a simple hydrothermal method to assemble CdS NWs decorated with Pt NPs onto rGO sheets using hydrazine as a reducing agent. Data regarding the morphology, structure and properties of the prepared nanocomposite were obtained through various characterization techniques including field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible and photoluminescence spectroscopy (PL). Assessing the electrocatalytic activity using cyclic voltammetry (CV) and amperometry techniques revealed that the ternary hybrid (rGO/CdS NWs/Pt NPs) exhibited superior electrocatalytic activity toward ethanol oxidation in alkaline solution with a more negative onset potential compared to nanostructures with various components such as CdS NWs, rGO/CdS NWs, CdS NWs/Pt NPs and rGO/Pt NPs. Furthermore, experiments using low-power LED as a visible-light illumination source showed a dramatic increase in the electrocatalytic activity of the proposed nanohybrid toward ethanol oxidation accompanied by a shift of the onset potential to a more negative potential of −0.950 V vs. Ag/AgCl compared to −0.870 V in dark condition. This high electrocatalytic and photoelectrocatalytic performance can be ascribed to providing maximum interfacial contact of CdS NWs with rGO, which decreases the agglomeration of nanostructures and suppresses the photogenerated electron–hole recombination. Furthermore, accelerated electron transfer in the presence of rGO and enhanced specific surface area achieved by uniform deposition of Pt NPs onto CdS NWs contribute to increasing the catalytic activity. This research could promise a simple strategy toward the synthesis of a one-dimensional semiconductor–rGO/Pt ternary hybrid and its applications as an efficient visible-light photocatalyst for different chemical transformation and energy conversion devices.