Search

Chemical Oxygen Demand (COD), as a detection indicator of water pollution, is of particular importance in assessing organic pollution in water. Furthermore, accurate and simple measuring COD methods are essential for water quality assessment and pollution control. However, the photoelectrochemical oxygen demand (PECOD) measurement, as one of the measuring COD methods, is affected by the reaction of water splitting, which is one of the hindrances to the commercialization of the analytical method of the PeCOD measurement. Hence, to overcome this challenge, a new PANI/Ti:Fe2O3 photoanode is constructed by hydrothermal and photoelectrochemical (PEC) deposition methods and investigated their optical properties and photoactivity. Under optimization conditions, it is discovered that the oxidation of organic compounds produces a net steady‐state current (inet) is directly proportional to COD concentration, with a detection limit of 1 mM glucose solution and a wide linear detection range of 1–78.125 mM, which is suitable for high concentration of glucose detection. As has been noted, PANI/Ti:Fe2O3 photoanode overcomes the obstacles to the practical application and eventual commercialization of the PECOD technology. [ABSTRACT FROM AUTHOR]

BiVO4 is one of the most promising photoanode materials for photoelectrochemical (PEC) solar energy conversion, but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency (LHE), weak photogenerated charge separation efficiency (ΦSep), and low water oxidation efficiency (ΦOX). Herein, we tackle these challenges of the BiVO4 photoanodes using systematic engineering, including catalysis engineering, bandgap engineering, and morphology engineering. In particular, we deposit a NiCoOx layer onto the BiVO4 photoanode as the oxygen evolution catalyst to enhance the ΦOX of Fe‐g‐C3N4/BiVO4 for PEC water oxidation, and incorporate Fe‐doped graphite‐phase C3N4 (Fe‐g‐C3N4) into the BiVO4 photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm, increase the LHE and ΦSep, and further improve the oxygen evolution reaction activity of the NiCoOx catalytic layer. Consequently, the maximum photocurrent density of the as‐prepared NiCoOx/Fe‐g‐C3N4/BiVO4 is remarkably boosted from 4.6 to 7.4 mA cm−2. This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE, ΦSep, and ΦOX of BiVO4‐based photoanodes, which will substantially benefit the design, preparation, and large‐scale application of next‐generation high‐performance photoanodes. [ABSTRACT FROM AUTHOR]

Boosting oxygen evolution reaction by local surface plasmon resonance (LSPR) provides breakthrough opportunities for the promotion of solar energy conversion; the potential of LSPR, however, has rarely been tapped and investigated. Here, we report the precise regulation of commercial Au nanoparticles plasmonic nanomaterial and OER electrocatalysts, viz. the NiCoOx electrocatalytic layer with hole transport ability and photothermal effect is prepared on the surface of Au nanoparticles by photoelectrodeposition. The NiCoOx layer not only increases the transmission distance of holes generated by plasmonic Au nanoparticles, but also reduce the agglomeration of plasmonic Au nanoparticles during long‐time OER reaction, which greatly improves the OER catalytic ability. The current density of NiCoOx/Au anode achieves 16.58 mA cm−2 at 2.0 V versus RHE, which is about 6.5 times of pristine NiCoOx anode (2.56 mA cm−2) and 47 times of pristine Au anode (0.35 mA cm−2). More importantly, with the LSPR and photothermal effect of plasmonic Au nanoparticles, the NiCoOx/Au anode provides additional current density of 7.01 mA cm−2 after illumination, and maintains no attenuation for more than 2000 s. Benefiting from the solution of agglomeration problem of plasmonic Au nanoparticles in the long‐time OER process and the effective utilization of generated holes of plasmonic Au nanoparticles, this design can provide guidance for the application of plasmonic materials in the field of electrocatalysis. [ABSTRACT FROM AUTHOR]

BiVO 4 -based photoanode is one of the most promising photoanodes for photoelectrocatalytic water splitting. However, the serious problem of interface charge recombination limits its further development. Here, a Mo:BiVO 4 /NiO x /CPF-TCzB/NiCoBi photoanode is constructed with double hole transport layer and an energy level gradient to achieve an effective photo-generated holes extraction and accumulation at the surface electrocatalyst. The conjugated polycarbazole framework CPF-TCzB is used as hole transport layer to eliminate the charge recombination center between Mo:BiVO 4 and NiCoBi electrocatalyst and realize the extraction and storage of photo-generated hole; NiO x nanoparticles are further inserted between Mo:BiVO 4 and CPF-TCzB to form a gradient energy level, eliminating the energy level barrier and optimizing band alignment. As a result, Mo:BiVO 4 /NiO x /CPF-TCzB/NiCoBi achieves a much higher photocurrent densities of 3.14 mA cm -2 than that of Mo:BiVO 4 (0.42 mA cm -2 ) at 0.6 V versus RHE. This work provides an specific way to adjust the band structure of BiVO 4 -based photoanodes and realize efficient hole extraction and storage for PEC water splitting., (© 2024 Wiley‐VCH GmbH.)