Tuning nanosheet Fe₂O₃ photoanodes with C₃N₄ and p-type CoO_x decoration for efficient and stable water splitting

Abstract

Fe2O3 photoanodes are ideal candidates for photoelectrochemical (PEC) water splitting.

Fe2O3/FePO4/FeOOH Ternary Stepped Energy Band Heterojunction Photoanode with Cascade‐Driven Charge Transfer and Enhanced Photoelectrochemical Performance

“…n is determined by whether the sample is a direct transition semiconductor or an indirect transition semiconductor. Fe 2 O 3 and FeOOH exhibit indirect transition, so n =4 [29,37] . However, FePO 4 exhibits direct transition, so the n =1 [38,39] .…”

“…The band gap energies of Fe 2 O 3 , FeOOH, and FePO 4 could be estimated by using Equation : [29] …”

“…Fe 2 O 3 and FeOOH exhibit indirect transition, so n = 4. [29,37] However, FePO 4 exhibits direct transition, so the n = 1. [38,39] As shown in Figure 4b, the bandgap energies (E g ) of Fe 2 O 3 , FeOOH, and FePO 4 were about 2.13 eV, 2.19 eV, and 2.35 eV, respectively, which is consistent with reported results.…”

“…[22][23][24] Constructing heterojunction is an efficient strategy, which could inhibit the recombination of charge carrier in Fe 2 O 3 photoanode by enhancing the electrons and holes separation. [26][27][28][29] The conduction band of FeOOH is higher than that of Fe 2 O 3 , and its valence band is lower than that of Fe 2 O 3 . [30] They have staggered energy band structure and can form type II heterojunction.…”

“…In recent decades, researchers have sought to develop methods to improve the electron‐hole separation efficiency of Fe 2 O 3 by methods such as controlling surface morphology, ion doping, and loading of cocatalysts [22–24] . Constructing heterojunction is an efficient strategy, which could inhibit the recombination of charge carrier in Fe 2 O 3 photoanode by enhancing the electrons and holes separation [26–29] . The conduction band of FeOOH is higher than that of Fe 2 O 3 , and its valence band is lower than that of Fe 2 O 3 [30] .…”