Design of SnO2:Ni,Ir Nanoparticulate Photoelectrodes for Efficient Photoelectrochemical Water Splitting

Abstract

Currently, hydrogen generation via photocatalytic water splitting using semiconductors is regarded as a simple environmental solution to energy challenges. This paper discusses the effects of the doping of noble metals, Ir (3.0 at.%) and Ni (1.5–4.5 at.%), on the structure, morphology, optical properties, and photoelectrochemical performance of sol-gel-produced SnO2 thin films. The incorporation of Ir and Ni influences the position of the peaks and the lattice characteristics of the tetragonal polycrystalline SnO2 films. The films have a homogeneous, compact, and crack-free nanoparticulate morphology. As the doping level is increased, the grain size shrinks, and the films have a high proclivity for forming Sn–OH bonds. The optical bandgap of the un-doped film is 3.5 eV, which fluctuates depending on the doping elements and their ratios to 2.7 eV for the 3.0% Ni-doped SnO2:Ir Photoelectrochemical (PEC) electrode. This electrode produces the highest photocurrent density (Jph = 46.38 mA/cm2) and PEC hydrogen production rate (52.22 mmol h−1cm−2 at −1V), with an Incident-Photon-to-Current Efficiency (IPCE% )of 17.43% at 307 nm. The applied bias photon-to-current efficiency (ABPE) of this electrode is 1.038% at −0.839 V, with an offset of 0.391% at 0 V and 307 nm. These are the highest reported values for SnO2-based PEC catalysts. The electrolyte type influences the Jph values of photoelectrodes in the order Jph(HCl) > Jph(NaOH) > Jph(Na2SO4). After 12 runs of reusability at −1 V, the optimized photoelectrode shows high stability and retains about 94.95% of its initial PEC performance, with a corrosion rate of 5.46 nm/year. This research provides a novel doping technique for the development of a highly active SnO2-based photoelectrocatalyst for solar light-driven hydrogen fuel generation.

Photocatalytic Degradation of Methyl Orange and Methylene Blue Dyes by Engineering the Surface Nano-Textures of TiO2 Thin Films Deposited at Different Temperatures via MOCVD

“…The sample deposited at 250 °C was supposed to have a smaller thickness compared to that of the sample deposited at 350 °C, which has been reported for samples deposited under the same conditions [ 24 ]. From the following relation, the absorption coefficient, α , was calculated, where d is the thickness, R is the reflectance, and T is the transmittance of the film [ 25 ]. It should be noticed that this relation neglects the interference effect, which was used in the envelope method.…”

The Impact of Co Doping and Annealing Temperature on the Electrochemical Performance and Structural Characteristics of SnO2 Nanoparticulate Photoanodes

“…The percentage of PEC-produced charges that contributed to the resulting photocurrent per absorbed photon is known as the APCE%. APCE is calculated by Equation (6) [ 8 , 41 ]: where A( λ ) is the optical absorbance. Figure 8 c demonstrates the change of APCE% versus the incident λ .…”

“…Therefore, it may be used for solar energy applications, such as the production of photoelectrochemical (PEC) H 2 , if it is made with more surface area and optical absorption in the UV/Vis region. Consequently, SnO 2 is attracting continuous interest for utilisation in optoelectronic devices, sensors, capacitors, Li-ion batteries, UV photocatalytic, and as an electrode material for energy conversion [ 3 , 4 , 6 , 7 , 8 , 9 ].…”

“…Similarly, Khan et al [ 2 ] reported the total removal of 4-Nitrophenol in less than 5 min by using the chemically prepared Fe-SnO 2 NPs. The crystallinity of chemically produced SnO 2 NPs is increased, the rate at which electron/hole pairs recombine is decreased, and the photocatalytic activity toward RhB, when exposed to visible light, is increased, according to Toloman et al [ 8 ].…”

Fabrication and Characterization of Nanostructured Rock Wool as a Novel Material for Efficient Water-Splitting Application

“…The rapid growth in the amount of H2 indicated the excellent stability of the RW>0.3 photoelectrodes. In addition, Table 2 shows a comparison between our optimized RW nanocatalyst and recently reported nanotextured catalysts [94][95][96][97][98][99][100][101][102][103][104]. The comparison is carried out in terms of photocatalyst composition, electrolyte, light power or source and catalytic performance parameters (H 2 moles, J ph or IPCE% values).…”