skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Facilitated electron transfer by Mn dopants in 1-dimensional CdS nanorods for enhanced photocatalytic hydrogen generation
Using sunlight to produce hydrogen gas via photocatalytic water splitting is highly desirable for green energy harvesting and sustainability. In this work, Mn 2+ doped 1-dimensional (1D) CdS nanorods (NRs) with Pt tips ( i.e. , 1D Mn:CdS-Pt NRs) were synthesized for photocatalytic water splitting to generate hydrogen gas. The incorporation of Mn 2+ dopants inside the 1D CdS NRs with a significantly longer lifetime (∼ms) than that of host excitons (∼ns) facilitates charge separation; the electron transfer to metal Pt tips leads to enhanced photocatalytic activity in water splitting redox reactions. The as-synthesized Mn 2+ doped CdS NR-based photocatalyst generated an order of magnitude greater yield of hydrogen gas compared to the undoped CdS NR-based photocatalyst. The enhanced charge transport from the long lifetime excited state of Mn 2+ dopants in light harvesting semiconductor nanomaterials presents a new opportunity to increase the overall photocatalytic performance.  more » « less
Award ID(s):
2052611 1944978
PAR ID:
10425309
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
Volume:
11
Issue:
13
ISSN:
2050-7488
Page Range / eLocation ID:
7066 to 7076
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Photocatalysis, mainly using TiO2 as a catalyst, has emerged as a promising method to address the issue of wastewater treatment. This study explores the enhanced photocatalytic activity of TiO2 through the introduction of reduced graphene oxide (rGO) and cadmium sulfide (CdS) as selective metal dopants. The incorporation of rGO and CdS into the TiO2 lattice aims to optimize its photocatalytic properties, including bandgap engineering, charge carrier separation, and surface reactivity. The unique combination of CdS and rGO with TiO2 is expected to boost degradation efficiency and reduce the reliance on expensive and potentially harmful sensitizers. This experimental investigation involves the synthesis and characterization of TiO2-based photocatalysts. The photocatalytic degradation of methyl orange (MO) and methylene blue (MB) was assessed under controlled laboratory conditions, studying the influence of metal dopants on degradation kinetics and degradation efficiency. Furthermore, the synthesized photocatalyst is characterized by advanced techniques, including BET, SEM, TEM, XRD, and XPS analyses. The degraded samples were analyzed by UV-Vis spectroscopy. Insights into the photoexcitation and charge transfer processes shed light on the role of metal dopants in enhancing photocatalytic performance. The results demonstrate the potential of a TiO2-rGO-CdS-based photocatalyst in which 100% degradation was achieved within four hours for MO and six hours for MB, confirming efficient azo dye degradation. The findings contribute to understanding the fundamental principles underlying the photocatalytic process and provide valuable guidance for designing and optimizing advanced photocatalytic systems. Ultimately, this research contributes to the development of sustainable and effective technologies for removing azo dyes from various wastewaters, promoting environmental preservation and human well-being. 
    more » « less
  2. null (Ed.)
    As a promising technology for sustainable hydrogen generation, photocatalytic (PC) and photoelectrochemical (PEC) water splitting have gathered immense attention over a half-century. While many review articles have covered extensive research achievements and technology innovations in water splitting, this article focuses on illustrating how the ferroelectric polarization influences charge separation and transportation in photocatalyst heterostructures during PC and PEC water splitting. This article first discusses the fundamentals of PC and PEC water splitting and how these electrochemical processes interact with the ferroelectric polarization-induced interfacial band bending, known as piezotronics. A few representative ferroelectric material-based heterogeneous photocatalyst systems are then discussed in detail to illustrate the effects of polarization, space charge region, and free charge concentration, which are critical factors determining the ferroelectric influences. Finally, a forward looking statement is provided to point out the research challenges and opportunities in this promising interdisciplinary research field between ferroelectrics and electrochemistry for clean energy applications. 
    more » « less
  3. Abstract Metal‐Organic Frameworks (MOFs) recently emerged as a new platform for the realization of integrated devices for artificial photosynthesis. However, there remain few demonstrations of rational tuning of such devices for improved performance. Here, a fast molecular water oxidation catalyst working via water nucleophilic attack is integrated into the MOF MIL‐142, wherein Fe3O nodes absorb visible light, leading to charge separation. Materials are characterized by a range of structural and spectroscopic techniques. New, [Ru(tpy)(Qc)(H2O)]+(tpy = 2,2′:6′,2″‐terpyridine and Qc = 8‐quinolinecarboxylate)‐doped Fe MIL‐142 achieved a high photocurrent (1.6 × 10−3A·cm−2) in photo‐electrocatalytic water splitting at pH = 1. Unassisted photocatalytic H2evolution is also reported with Pt as the co‐catalyst (4.8 µmol g−1min−1). The high activity of this new system enables hydrogen gas capture from an easy‐to‐manufacture, scaled‐up prototype utilizing MOF deposited on FTO glass as a photoanode. These findings provide insights for the development of MOF‐based light‐driven water‐splitting assemblies utilizing a minimal amount of precious metals and Fe‐based photosensitizers. 
    more » « less
  4. Abstract Hydrogen gas is a prominent focus in pursuing renewable and clean alternative energy sources. The quest for maximizing hydrogen production yield involves the exploration of an ideal photocatalyst and the development of a simple, cost‐effective technique for its generation. Iron titanate has garnered attention in this context due to its photocatalytic properties, affordability, and non‐toxic nature. Over the years, different synthesis routes, different morphologies, and some modifications of iron titanate have been carried out to improve its photocatalytic performance by enhancing light absorption in the visible region, boosting charge carrier transfer, and decreasing recombination of electrons and holes. The use of iron titanate photocatalyst for hydrogen evolution reaction has seen an upward trend in recent times, and based on available findings, more can be done to improve the performance. This review paper provides a comprehensive overview of the fundamental principles of photocatalysis for hydrogen generation, encompassing the synthesis, morphology, and application of iron titanate‐based photocatalysts. The discussion delves into the limitations of current methodologies and present and future perspectives for advancing iron titanate photocatalysts. By addressing these limitations and contemplating future directions, the aim is to enhance the properties of materials fabricated for photocatalytic water splitting. 
    more » « less
  5. Photoelectrochemical (PEC) hydrogen generation is a promising solar energy harvesting technique to address the concerns about the ongoing energy crisis. Antimony selenide (Sb2Se3) with van der Waals‐bonded quasi‐1D (Q1D) nanoribbons, for instance, (Sb4Se6)n, has attracted considerable interest as a light absorber with Earth‐abundant elements, suitable bandgap, and a desired sunlight absorption coefficient. By tuning its anisotropic growth behavior, it is possible to achieve Sb2Se3films with nanostructured morphologies that can improve the light absorption and photogenerated charge carrier separation, eventually boosting the PEC water‐splitting performance. Herein, high‐quality Sb2Se3films with nanorod (NR) array surface morphologies are synthesized by a low‐cost, high‐yield, and scalable close‐spaced sublimation technique. By sputtering a nonprecious and scalable crystalline molybdenum sulfide (MoS2) film as a cocatalyst and a protective layer on Sb2Se3NR arrays, the fabricated core–shell structured MoS2/Sb2Se3NR PEC devices can achieve a photocurrent density as high as −10 mA cm−2at 0 VRHEin a buffered near‐neutral solution (pH 6.5) under a standard simulated air mass 1.5 solar illumination. The scalable manufacturing of nanostructured MoS2/Sb2Se3NR array thin‐film photocathode electrodes for efficient PEC water splitting to generate solar fuel is demonstrated. 
    more » « less