Quantum Dot Monolayer Sensitized ZnO Nanowire‐Array Photoelectrodes: True Efficiency for Water Splitting

Abstract

A photoconversion efficiency of 1.83 % was observed for a photodevice based on ZnO nanowires sensitized with CdTe quantum dots (QDs; see picture; FTO=F‐doped SnO2), which is more than 200 % greater than that of pristine ZnO nanowires. The presence of CdTe QDs on the surface of ZnO nanowires was confirmed by HRTEM and elemental mapping.

A visible light induced photoelectrochemical aptsensor constructed by aligned ZnO@CdTe core shell nanocable arrays/carboxylated g-C3N4 for the detection of Proprotein convertase subtilisin/kexin type 6 gene

“…CdTe can form a band alignment with ZnO, which allowed effective injection of photogenerated electrons from CdTe into ZnO (Chen et al 2010;). …”

V ions implanted ZnO nanorod arrays for photoelectrochemical water splitting under visible light

“…The seeded substrates were suspended horizontally in a mixed aqueous solution of zinc nitrate (0.05 M) and hexamethylenetetramine (0.05 M) in an 100 mL Teflon-lined autoclave, heated to 90 C for 24 h. The obtained white ZnO films were then annealed at 500 C for 2 h with a ramping rate of 2 C/min. V ions were implanted into the ZnO NRs by metal vapor vacuum arc (MEVVA) ion source implanter [10,11]. This synthesis procedure was carried out at room temperature with accelerator voltage of 50 kV, and the nominal fluences were 2.5 Â 10 14 , 5 Â 10 14 , 1 Â 10 15 , 2.5 Â 10 15 and 5 Â 10 15 ions/ cm 2 , respectively.…”

“…However, only ultraviolet (UV) light can be utilized for solar water splitting due to its wide band gap (3.37 eV). During the past years, to utilize the much more energy contained in the visible light region than in the UV region of the sunlight [7], continuous efforts have been made to activate ZnO under visible light, such as cation and anion doping [8,9], quantum dots sensitization [10] and composite semiconductor [11], etc.…”

Large-scale patterned ZnO nanorod arrays for efficient photoelectrochemical water splitting

“…Among varieties of semiconductor candidates, ZnO is one of the advanced photoanode materials applied in PEC cells due chiefly to its appropriate band edge positions, extremely rich morphologies, strong oxidizing activity, facile synthesis and nontoxicity [11,18]. Additionally, the carrier mobility of ZnO is 10 to 100 times larger than that of TiO 2 , which facilitates the electron transfer and reduces electrical resistance [8,19].…”

“…However, most metal oxides are wide band gap semiconductors with poor absorption in visible region, thus limiting the photoconversion efficiency of the PEC cells. To this end, many light harvesting approaches have recently been proposed, such as doping [9,10], quantum dots sensitization [11,12], and heterostructure design [13,14].…”