Marković Smilja, Stojković Simatović Ivana, Ahmetović Sanita, Veselinović Ljiljana, Stojadinović Stevan, Rac Vladislav, Škapin Srečo Davor, Bajuk Bogdanović Danica, Janković Častvan Ivona, Uskoković Dragan
Institute of Technical Sciences of SASA Knez Mihailova 35/IV 11000 Belgrade Serbia
University of Belgrade, Faculty of Physical Chemistry Belgrade Serbia.
RSC Adv. 2019 Jun 3;9(30):17165-17178. doi: 10.1039/c9ra02553g. eCollection 2019 May 29.
ZnO nanopowders were produced using microwave processing of a precipitate and applied as a photoanode for photoelectrochemical water splitting. Two different surfactants, cetyltrimethylammonium bromide (CTAB) as the cationic and Pluronic F127 as the non-ionic one, were employed to adjust the surface-to-bulk defect ratio in the ZnO crystal structure and further to modify the photo(electro)catalytic activity of the ZnO photoanode. The crystal structure, morphological, textural, optical and photo(electro)catalytic properties of ZnO particles were studied in detail to explain the profound effects of the surfactants on the photoanode activity. The ZnO/CTAB photoanode displayed the highest photocurrent density of 27 mA g, compared to ZnO (10.4 mA g) and ZnO/F127 photoanodes (20 mA g) at 1.5 V SCE in 0.1 M NaSO under visible illumination of 90 mW cm. A significant shift of the overpotential toward lower values was also observed when photoanodes were illuminated. The highest shift of the overpotential, from 1.296 to 0.248 V SCE, was recorded when the ZnO/CTAB photanode was illuminated. The ZnO/CTAB photoanode provides efficient charge transfer across the electrode/electrolyte interface, with a longer lifetime of photogenerated electron-hole pairs and reduced possibility of charge recombination. The photoconversion efficiency was improved from 1.4% for ZnO and 0.9% for ZnO/F127 to 4.2% for ZnO/CTAB at 0.510 mV. A simple procedure for the synthesis of ZnO particles with improved photo(electro)catalytic properties was established and it was found that even a small amount of CTAB used during processing of ZnO increases the surface-to-bulk defect ratio. Optimization of the surface-to-bulk defect ratio in ZnO materials enables increase of the absorption capacity for visible light, rendering of the recombination rate of the photogenerated pair, as well as increase of both the photocurrent density and photoconversion efficiency.
通过对沉淀物进行微波处理制备了氧化锌纳米粉末，并将其用作光电化学水分解的光阳极。使用两种不同的表面活性剂，阳离子型的十六烷基三甲基溴化铵（CTAB）和非离子型的Pluronic F127，来调节氧化锌晶体结构中的表面与体相缺陷比，并进一步改变氧化锌光阳极的光（电）催化活性。详细研究了氧化锌颗粒的晶体结构、形态、织构、光学和光（电）催化性能，以解释表面活性剂对光阳极活性的深远影响。在90 mW/cm²可见光照射下，在0.1 M Na₂SO₄中，相对于氧化锌（10.4 mA/g）和氧化锌/F127光阳极（20 mA/g），氧化锌/CTAB光阳极在1.5 V SCE时显示出最高的光电流密度27 mA/g。当光阳极被光照时，还观察到过电位向更低值的显著偏移。当氧化锌/CTAB光阳极被光照时，记录到过电位的最大偏移，从1.296 V SCE降至0.248 V SCE。氧化锌/CTAB光阳极在电极/电解质界面提供了有效的电荷转移，光生电子-空穴对的寿命更长，电荷复合的可能性降低。在0.510 mV时，光转换效率从氧化锌的1.4%和氧化锌/F127的0.9%提高到氧化锌/CTAB的4.2%。建立了一种合成具有改善光（电）催化性能的氧化锌颗粒的简单方法，并且发现在氧化锌制备过程中使用少量的CTAB就能增加表面与体相缺陷比。优化氧化锌材料中的表面与体相缺陷比能够提高对可见光的吸收能力，降低光生对的复合率，同时提高光电流密度和光转换效率。
