Effects of annealing temperature on the physicochemical, optical and photoelectrochemical properties of nanostructured hematite thin films prepared via electrodeposition method

Effects of Heating Mode and Temperature on the Microstructures, Electrical and Optical Properties of Molybdenum Thin Films

“…Thus, they can fill up the microvoids and/or vacancies, resulting in better crystallinity and enhancing the particle growth [19]. The results are consistent with the conclusions in the literature [20]. On the other hand, as the substrate and annealing temperature increase, the densities of the crystallographic defects in Mo thin films also decrease rapidly, including dislocations, interstitials and vacancies [21].…”

Electrodeposited Ti-doped hematite photoanodes and their employment for photoelectrocatalytic hydrogen production in the presence of ethanol

“…Such fusion was more obvious in the doped sample where nanoparticles seem to stand on a compact mass layer [16]. This is the result of high temperature annealing, which is necessary in order to make efficient hematite films [14,17]. In this respect, electrochemically deposited hematite has a disadvantage compared to chemical vapor deposited films [5,10].…”

“…Another interesting approach is to combine hematite with an oxygen evolution co-catalyst, such as Co-Pi [7]. Electrodeposition is usually followed by high temperature annealing, which affects grain size and grain boundaries and, subsequently, overall photocatalyst performance [17]. In addition, it leads to unintentional doping with Sn deriving from the FTO (Fluorine doped Tin Oxide) substrate, which is usually employed as transparent electrode [14].…”

Electrochemically synthesized tungsten trioxide nanostructures for photoelectrochemical water splitting: Influence of heat treatment on physicochemical properties, photocurrent densities and electron shuttling

“…This could effectively prolong the recombination of electron-hole pairs at the surfaces of WO 3 , leading to an enhancement in the overall PEC-assisted water splitting efficiency. Phuan et al [11] explained that this was thermodynamically linked to an increase in average WO 3 crystallite size and to the reduction of WO 3 grain boundaries during the thermally induced phase transition, leading to suppression of the electron-hole pair recombination rate. Overall, the WO 3 thin film treated at 600°C was found to be optimal due to an increase in average WO 3 crystal size, fewer voids, and the suppression of electron-hole pairs recombination that allowed lower resistance and higher photocurrent flows at molecular level.…”

“…In PEC-assisted water splitting, the redox reaction is directly related to the positions of the valence band (VB) and conduction band (CB) of the semiconductor photocatalyst employed [11]. The CB position of the WO 3 photocatalyst makes it unsuitable for use as a cathodic hydrogen-evolution catalyst (HEC); however, the comparatively ideal position of the WO 3 VB illustrates its suitability for use at the anodic OEC [12].…”