Search Results

You searched for all publications:

with publication states 'Published (Approved)'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

2 items found (0 items not approved), displaying all items.1

Instruments / Technical Area	Publication Details	Published	Actions
E01-JEM ARM 200CF	Nitrogen-doped carbon dots/TiO2 nanoparticle composites for photoelectrochemical water oxidation Hui Luo , Stoichko D. Dimitrov , Matyas Daboczi , Ji-seon Kim , Qian Guo , Yuanxing Fang , Marc-antoine Stoeckel , Paolo Samorì , Oliver Fenwick , Ana Belen Jorge Sobrido , Xinchen Wang , Maria-magdalena Titirici Acs Applied Nano Materials DOI: 10.1021/acsanm.9b02412 Diamond Proposal Number(s): [22447] Show Abstract ▼ Abstract: Carbon dots on photoactive semiconductor nanomaterials have represented an effective strategy for enhancing their photoelectrochemical (PEC) activity. By carefully designing and manipulating carbon dots/support composite, a high photocurrent could be obtained. Currently, there is not much fundamental understanding of how the interaction between such materials can facilitate the reaction process. This hinders the wide applicability in PEC devices. To address this need of improving the fundamental understanding of carbon dots/semiconductor nanocomposite, we have taken the TiO2 case as a model semiconductor system with nitrogen-doped carbon dots (NCDs). We present here with in-depth investigation of the structural hybridization and energy transitions in the NCDs/TiO2 photoelectrode via high-resolution scanning transmission microscopy (HR-STEM), electron energy loss spectroscopy (EELS), UV-Vis absorption, electrochemical impedance spectroscopy (EIS), Mott-Schottky (M-S), time-correlated single photon counting (TCSPC) and ultra-violet photoelectron spectroscopy (UPS), which shed some light on the charge transfer process at the carbon dots and TiO2 interface. We show that N doping in carbon dots can effectively prolong the carrier lifetime, and the hybridisation of NCDs and TiO2 is able not only to extend TiO2 light response into the visible range but also to form heterojunction at the NCDs/TiO2 interface with properly aligned band structure that allows a spatial separation of the charges. This work is arguably the first to report the direct probing of the band positions of carbon dots-TiO2 nanoparticle composite in a PEC system for understanding the energy transfer mechanism, demonstrating the favourable role of NCDs in the photocurrent response of TiO2 for water oxidation process. This study reveals the importance of combining structural, photophysical and electrochemical experiments to develop a comprehensive understanding of the charge injection/electronic communication between the carbon dots and their current collectors or catalyst supports.	Mar 2020
E01-JEM ARM 200CF	Manipulating the optical properties of carbon dots via fine tuning their structural features Hui Luo , Nikolaos Papaioannou , Enrico Salvadori , Maxie Roessler , Gereon Ploenes , Ernst R. H. Van Eck , Liviu Tanase , Jingyu Feng , Yiwei Sun , Yan Yang , Mohsen Danaie , Ana Jorge Sobrido , Andrei Sapelkin , James Durrant , Stoichko D. Dimitrov , Maria-magdalena Titirici Chemsuschem DOI: 10.1002/cssc.201901795 Diamond Proposal Number(s): [17587] Show Abstract ▼ Abstract: As a new class of sustainable carbon material, the term “carbon dots” represents an “umbrella term” as there are many types of materials included. We employ a broad range of techniques to develop understanding on hydrothermally synthesized carbon dots and show how fine tuning the structural features using simple reduction/oxidation reactions can drastically affect their excited state properties. Structural and spectroscopic studies found that photoluminescence originates from direct excitation of localized fluorophores involving oxygen functional groups, while the excitation at graphene‐like features leads to ultrafast phonon‐assisted relaxation and largely quenches the fluorescent quantum yields. This is arguably the first to identify the dynamics of photoluminescence including Stokes’ shift formation, allowing us to fully resolve the relaxation pathways in these carbon dots. The comprehensive investigation sheds light on how understanding the excited state relaxation processes in different carbon structure is crucial for tuning the optical properties for any potential commercial applications.	Aug 2019

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User