Hematite Surface Modification toward Efficient Sunlight-Driven Water Splitting Activity: The Role of Gold Nanoparticle Addition,The Journal of Physical Chemistry C

当前位置： X-MOL 学术 › J. Phys. Chem. C › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Hematite Surface Modification toward Efficient Sunlight-Driven Water Splitting Activity: The Role of Gold Nanoparticle Addition
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2020-03-11 , DOI: 10.1021/acs.jpcc.9b11966
Aryane Tofanello ₁ , Andre L. M. Freitas ₁ , Waldemir M. Carvalho ₁ , Turkka Salminen ₂ , Tapio Niemi ₃ , Flavio L. Souza ₁

Affiliation

Localized surface plasmon resonance has been investigated to enhance light harvesting in hematite-based photoelectrodes modified with gold nanoparticles (AuNPs); meanwhile, an extensive understanding about the different processes involved in the hematite–AuNP system remains unclear. This work addresses a majority of effects associated with AuNP addition by comparing charge transfer, catalytic and light harvesting efficiencies. The obtained results revealed that the lower AuNP amount leads to a higher photocurrent response of 1.20 mA cm^–2 at 1.23 V_RHE in comparison with all photoelectrodes designed here. X-ray photoelectron data revealed that hematite photoelectrodes loaded with higher concentrations of AuNPs immersed in an alkaline electrolyte showed hydrated/oxidized gold phase formation at the electrode/electrolyte interface. This change on the semiconductor–metal interface may affect the conductivity impairing the photocatalytic performance because of the passivation layer on the AuNP surface, decreasing the efficiency of charge transfer. Notoriously, increasing AuNP amount supported on the hematite surface clearly promoted higher light absorption, which was surprisingly not followed by photoelectrochemical efficiency. This result suggests here that the plasmon effect is not a dominant phenomenon that drives the photoelectrode performance. In fact, a deeper analysis showed that the loaded hematite photoelectrodes with low amounts of AuNPs provides a Schottky contact at the semiconductor–metal interface leading to Fermi level equilibration enhancing charge transport efficiency, which is classified as the predominant effect leading to higher photoresponse in the system.

中文翻译：

赤铁矿表面改性对高效的阳光驱动水分解活性：金纳米粒子添加的作用

已经研究了局部表面等离子体激元共振，以增强金纳米颗粒（AuNPs）修饰的赤铁矿基光电电极的光收集；同时，关于赤铁矿-AuNP系统涉及的不同过程的广泛理解仍然不清楚。这项工作通过比较电荷转移，催化和光收集效率来解决与AuNP添加有关的大多数影响。获得的结果表明，较低的AuNP量导致在1.23 V _RHE时具有1.20 mA cm ^–2的较高光电流响应与此处设计的所有光电极相比。X射线光电子数据表明，负载有较高浓度AuNPs的赤铁矿光电极浸没在碱性电解质中，在电极/电解质界面处形成了水合/氧化的金相。由于AuNP表面上的钝化层，半导体-金属界面上的这种变化可能会影响电导率，从而损害光催化性能，从而降低电荷转移的效率。众所周知，赤铁矿表面负载的AuNP含量的增加明显促进了更高的光吸收率，令人惊讶的是，光电化学效率并未随之提高。该结果在此表明，等离子体激元效应不是驱动光电电极性能的主要现象。事实上，

更新日期：2020-03-12

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南