Carrier engineering of Zr-doped Ta₃N₅ film as an efficient photoanode for solar water splitting

Abstract

Ta3N5 is regarded as a promising candidate material with adequate visible light absorption and band structure for photoelectrochemical water splitting. However, the performance of Ta3N5 is severely limited by the...

Reinforcement of Visible-Light Harvesting and Charge-Transfer Dynamics of BiVO4 Photoanode via Formation of p–n Heterojunction with CuO for Efficient Photoelectrocatalytic Water Splitting

“…where E RHE is potential vs RHE, E Ag/AgCl = 0.198 V at 25 °C, and E Ag/AgCl is experimentally measured potential against Ag/AgCl. 8,43 Applied bias photon-to-current efficiency (ABPE) of the BiVO 4 and BiVO 4 /CuO electrodes were calculated from the J−V curve by using the eq 2.…”

“…The measured potentials were converted to reversible hydrogen electrode (RHE) using eq with the measured pH of the electrolyte. where E RHE is potential vs RHE, E Ag/AgCl = 0.198 V at 25 °C, and E Ag/AgCl is experimentally measured potential against Ag/AgCl. , …”

Defect Engineering of Ta3N5 Photoanodes: Enhancing Charge Transport and Photoconversion Efficiencies via Ti Doping

“…This observation contrasts with previous studies of Zr-doped Ta 3 N 5 , where the introduction of Zr impurities favored the simultaneous formation of Zr Ta and O N as compensating acceptor and donor defects, respectively. [14,15,17] This important difference between Ti and Zr is likely due to the significantly higher oxygen affinity of Zr compared to Ti. [23] In addition to the Ti and O impurity concentrations, the N content is a crucial parameter since nitrogen vacancies (v N ) are known to be deep donors that act as deleterious recombination centers in Ta 3 N 5 .…”

“…[11,12] In addition, foreign atom doping has been extensively investigated and has led to remarkable performance advances. To date, a wide range of dopant elements, including Zr, [13][14][15] Mg, [16,17] Ge, [18] La, [19] Sc, [20] Na, [21,22] K, [21,22] Rb, [21] and Cs, [21] as well as co-doping with some of these elements, [17,19] have been explored. While several mechanisms have been proposed to describe corresponding improvements of the PEC characteristics of doped Ta 3 N 5 , most studies conclude that the primary role of these dopants is to modulate the concentrations and populations of native point defects (v N and Ta 3+ ), as well as the majority O N donor content.…”

“…A prominent example of this is Zrdoped Ta 3 N 5 , in which Zr 4+ incorporates on Ta 5+ sites (Zr Ta ) as a compensating electron acceptor, significantly reducing the concentrations of deep traps associated with both v N and Ta 3+ . [15,17] Increasing the Zr content also increases the concentration of O N , [14] with the defect pair possessing a lower formation energy than isolated Zr Ta . While this combined incorporation improves the overall performance of Ta 3 N 5 photoanodes, it limits independent control over the competing defect properties of Zr Ta and O N , and potentially restricts the tunable range of bulk conductivity.…”