Efficient Solar-Induced Photoelectrochemical Response Using Coupling Semiconductor TiO2-ZnO Nanorod Film

Abstract

Efficient solar driven photoelectrochemical (PEC) response by enhancing charge separation has attracted great interest in the hydrogen generation application. The formation of one-dimensional ZnO nanorod structure without bundling is essential for high efficiency in PEC response. In this present research work, ZnO nanorod with an average 500 nm in length and average diameter of about 75 nm was successfully formed via electrodeposition method in 0.05 mM ZnCl2 and 0.1 M KCl electrolyte at 1 V for 60 min under 70 °C condition. Continuous efforts have been exerted to further improve the solar driven PEC response by incorporating an optimum content of TiO2 into ZnO nanorod using dip-coating technique. It was found that 0.25 at % of TiO2 loaded on ZnO nanorod film demonstrated a maximum photocurrent density of 19.78 mA/cm2 (with V vs. Ag/AgCl) under UV illumination and 14.75 mA/cm2 (with V vs. Ag/AgCl) under solar illumination with photoconversion efficiency ~2.9% (UV illumination) and ~4.3% (solar illumination). This performance was approximately 3–4 times higher than ZnO film itself. An enhancement of photocurrent density and photoconversion efficiency occurred due to the sufficient Ti element within TiO2-ZnO nanorod film, which acted as an effective mediator to trap the photo-induced electrons and minimize the recombination of charge carriers. Besides, phenomenon of charge-separation effect at type-II band alignment of Zn and Ti could further enhance the charge carrier transportation during illumination.

ZnO@TiO2 Core Shell Nanorod Arrays with Tailored Structural, Electrical, and Optical Properties for Photovoltaic Application

“…Since it is known from literature [6,7,14,15,16,17,18] that ZnO@TiO 2 core–shell nanostructures could serve as an advantageous electron transport layer in perovskite, polymer, and dye sensitized solar cells, influence of the morphology and structure on electrical and optical properties, that are crucial for photovoltaic application, were studied. To obtain ZnO@TiO 2 core–shell nanostructures with diverse structural properties, different deposition techniques were applied for the preparation of the shell layer, and the deposition parameters were additionally varied.…”

“…These hetero-structures combine stable characteristics from the shell and fast electron transport features of the mono-crystalline nanowire core, thus increasing the efficiency of solar cells. Samad et al [15] found that an enhancement of photocurrent density and photo conversion efficiency occurred due to the sufficient Ti content within TiO 2 –ZnO nanorod films. This film traps the photo-induced electrons and minimizes the recombination of charge carriers, while the charge-separation effect at the type-II band alignment of Zn and Ti further enhances the charge carrier transport during illumination.…”

Photocatalytic Pretreatment of Commercial Lignin Using TiO2-ZnO Nanocomposite-Derived Advanced Oxidation Processes for Methane Production Synergy in Lab Scale Continuous Reactors

“…The results demonstrated that the samples were in line, indicating TiO2-ZnO phase. It can be confined that the TiO2 particles in the samples are identified as anatase phase for the sharp diffraction peaks located at 2 Meanwhile it also has some ZnO diffraction peaks located at 2 theta 31.7°, 34.5°, 36.3° and 69.05°, which correspond to the (100), (002), (101) and (201) crystal planes, respectively [20]. There was significant difference in peaks of different molar ratios of TiO2-ZnO nanocomposite.…”

“…Thus, ZnO and TiO2-ZnO were annealed at 500 °C [21]. Moreover, most diffraction peaks Meanwhile it also has some ZnO diffraction peaks located at 2 theta 31.7 • , 34.5 • , 36.3 • and 69.05 • , which correspond to the (100), (002), (101) and (201) crystal planes, respectively [20]. There was significant difference in peaks of different molar ratios of TiO 2 -ZnO nanocomposite.…”

Broadband NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2 Nanoparticles Anchored on SiO2/Carbon Electrospun Fibers for Photocatalytic Degradation of Organic Pollutants

“…Recently, nanosized TiO 2 has received extensive attention because of its excellent photocatalytic activity under ultraviolet (UV) light irradiation, high chemical stability, environmental friendliness, and low cost. − Nevertheless, the photocatalytic reaction in the presence of TiO 2 can be triggered only under a narrow UV light range due to the optical band gap (3.2 eV) of TiO 2 . To extend the photoresponse range to the visible light region, various feasible methods have been explored, such as metal or nonmetal doping, − deposition of noble metals, − and coupling with other semiconductors. − …”