Co和P掺杂对α-Fe_2O_3光电化学催化分解水的影响

在众多光阳极材料中,纳米结构材料α-Fe_2O_3由于其光吸收显著、化学稳定性好、储量丰富等优势,被认为是最有前途的材料之一。利用水热法制备了具有良好光解水性能的Co和P掺杂α-Fe_2O_3纳米材料。经过掺杂后α-Fe_2O_3纳米材料仍为纳米棒状形貌,纳米棒的粒径增加。实验发现,Co掺杂α-Fe_2O_3制成的电极在标准光照射下的最大光生电流密度为0.453 m A/cm2,是未掺杂样品的20.6倍,P掺杂α-Fe_2O_3制成的电极在标准光照射下的最大光生电流密度为0.276 m A/cm2,是未掺杂样品的12.5倍,具备了高效光解水性能。同时通过SEM、TEM、XRD、UV-Vis和Mott-Schottky测试等方法,结合形貌与结构表征,研究了α-Fe_2O_3的光电化学分解水性能影响机理。

NiFe layered double-hydroxide nanoparticles for efficiently enhancing performance of BiVO_4 photoanode in photoelectrochemical water splitting

A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.

Enabling practical electrocatalyst-assisted photoelectro- chemical water splitting with earth abundant materials

Sustainable development and continued prosperity of humanity hinge on the availability of renewable energy sources on a terawatts scale. In the long run, solar energy is the only source that can meet this daunting demand. Widespread utilization of solar energy faces challenges as a result of its diffusive （hence low energy density） and intermittent nature. How to effectively harvest, concentrate, store and redistribute solar energy constitutes a fundamental challenge that the scientific community needs to address. Photoelectrochemical （PEC） water splitting is a process that can directly convert solar energy into chemical energy and store it in chemical bonds, by producing hydrogen as a clean fuel source. It has received significant research attention lately. Here we provide a concise review of the key issues encountered in carrying out PEC water splitting. Our focus is on the balance of considerations such as stability, earth abundance, and efficiency. Particular attention is paid to the combination of photoelectrodes with electrocatalysts, especially on the interfaces between different components.