A hybrid bulk-heterojunction photoanode for direct solar-to-chemical conversion

Abstract

Organic semiconductors (OSs) are emerging candidates as light-harvesting materials in photoelectrochemical (PEC) cells for direct solar-to-chemical conversion. Despite significant recent progress with OS-based photocathodes, the development of efficient and stable...

In Situ Determination of Polaron-Mediated Ultrafast Electron Trapping in Rutile TiO2 Nanorod Photoanodes

“…Accelerating the kinetics of water oxidation at the semiconductor–electrolyte interface is one of the key factors to improve the efficiency of metal oxides such as TiO 2 and α-Fe 2 O 3 for photoelectrochemical water splitting, which is limited by the variance between the ps–ns lifetimes of photogenerated electrons and holes in metal oxides versus the μs–s time scale of water oxidation, − while the ps–ns lifetimes of the photogenerated electrons coincide with the lifetime of small polarons (ns scale) in rutile TiO 2 , indicating the constructive interaction between polaron and photogenerated electrons, as in other materials. − Recently, many efforts have been developed to prolong the lifetime of inherently short-lived charge carriers for driving the slower kinetics of water oxidation, including heterojunction construction, − cocatalyst deposition, , surface state mediation, − and so on. However, the lack of monitoring the charge carrier dynamics in semiconductor photoanodes restricts the development of PEC applications.…”

Polymer Photoelectrodes for Solar Fuel Production: Progress and Challenges

“…This photoanode (ITO/PBDB-T/ITIC/GaIn@Ni/NiFe-LDHs) exhibited a record water oxidation photocurrent density of 15.1 mA/cm 2 at 1.23 V vs RHE . Similarly, a BHJ-based photoanode was prepared using a covalent polymer network (CPN) and SnO 2 , and the photocurrent density of 3.3 mA/cm 2 at 0.54 V vs RHE was obtained at pH 0 . In addition, a BHJ made up of benzodithiophene-based polymer PBDTTTPD and naphthalenediimide-based polymer PNDITCVT was reported for PEC water oxidation.…”

“…116 Similarly, a BHJ-based photoanode was prepared using a covalent polymer network (CPN) and SnO 2 , and the photocurrent density of 3.3 mA/cm 2 at 0.54 V vs RHE was obtained at pH 0. 117 In addition, a BHJ made up of benzodithiophene-based polymer PBDTTTPD and naphthalenediimide-based polymer PNDITCVT was reported for PEC water oxidation. The BHJ after loading water oxidation catalyst Co 3 O 4 showed a photocurrent density of 2 mA/cm 2 at 1.23 V vs RHE at pH 9.0.…”

Host/Guest Nanostructured Photoanodes Integrated with Targeted Enhancement Strategies for Photoelectrochemical Water Splitting

“…In type-II heterojunctions, photogenerated electrons transfer from the conduction band (CB) of guest materials to the more conductive host materials and finally reach the counter electrode, while holes facilely move in the opposite direction, thus resulting in a spatial separation of electron-hole pairs and a depressed charge recombination. [100][101][102][103] Lee et al investigated the construction of heterojunction films consisting of guest BiVO 4 with a series of host materials, such as Fe 2 O 3 , TiO 2 , SnO 2 , and WO 3 . [104] As shown in Figure 4a, SnO 2 /BiVO 4 and WO 3 /BiVO 4 host/guest films can form a type-II heterojunction due to the matched band alignment.…”