Cardiff University School of Earth and Ocean Sciences Nanoparticulate Nickel Sulfide By Shanshan Huang Thesis submitted for the Degree of Philosophiae Doctor July 2008 UMI Number: U585143 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI U585143 Published by ProQuest LLC 2013. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 CARDIFF UNIVERSITY PRIFYSGOL C a ERDY|§> DECLARATION This work has not previously been accepted in substance for any degree and is not concurrently submitted in candidature for any degree. S ig n e d .......................(candidate) Date ...<^4 / p .i /.?.$. .... STATEMENT 1 This thesis is being submitted in partial fulfillment of the requirements for the degree o f P/uD ..........................(insert MCh, MD, MPhil, PhD etc, as appropriate) Signed ... ..................... ..H fw y ........................... (candidate) Date ...PMtf.lP.%................... STATEMENT 2 This thesis is the result of my own independent work/investigation, except where otherwise stated. Other sources are acknowledged by explicit references. S ig n e d : .......................(candidate) Date .. .Pft!.??.(P.S.... STATEMENT 3 I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organisations. S ig n ed ........................(candidate) Date .... STATEMENT 4: PREVIOUSLY APPROVED BAR ON ACCESS I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loans after expiry of a bar on access previously approved by the Graduate Development Committee. S ig n ed ....... (candidate) Date Abstract Nickel sulfide possesses a variety of typical structures and stoichiometries that distinguish itself from iron sulfide and exhibits unique roles in the prebiotic reactions which are proposed to be involved in the origin of life. Nickel sulfide precipitate is hydrated and nanocrystalline, modelled as a 4 nm sphere with a 1 nm crystalline and anhydrous NiS (millerite) core, surrounded by a hydrated and defective mantle phase. It is a metastable but fairly robust structural configuration. It may be formulated as NiSxfhO; x approxim ates to 1.5 and decreases on heating. The fresh nanoparticulate nickel sulfide precipitates undergo structural transformation from the initial millerite-like NiS to the more crystalline polydymite-like Ni 3S4 . This reaction is accompanied by the formation of a less crystalline Ni 3S2 (heazlewoodite) phase. The reaction, happening in ambient conditions, occurs more readily for the solids precipitated from acidic environments (i.e., pH 3) and may be facilitated by the hydrogen and water bonding contained in this material. The performance of nickel sulfide and iron sulfide precipitates is investigated in the formaldehyde world under ambient and sulfidic environments which mimic the ambient ancient Earth environments to some extent. The catalytic capacity of the metal sulfides is not obvious in these experiments. An interesting finding is that, trithiane, the cyclic (SCH 2)3, also suppresses the pyrite formation and thus promotes the greigite formation in the reaction between FeS and H 2S. This provides another cause for the greigite formation in the Earth sedimentary systems and adds information to the origin-of-life theory in the iron sulfur world. Voltammetry experiments reveal that the nickel-cysteine complex lowers the overpotential for molecular H 2 evolution in sea water to -1.53 V under ambient conditions. This catalytic property of the abiotic nickel-cysteine complex apparently mimics the Ni-S core in some hydrogenase enzymes functioning in physiological conditions. This bridges the abiotic and biotic worlds and supports the idea that life originated in the prebiotic ancient ocean. Acknowledgements I thank my supervisor David Rickard for his support, encouragement and care, and Anthony Oldroyd for his help and friendship. I thank Kenneth Harris who helped me out at a low point and provided generous support on my project. I appreciate the support from my pastoral supervisor Carrie Lear. My second supervisor was Simon Wakefield. The work was funded by the Dorothy Hodgkin Foundation. I am grateful to Ian Butler for his kind help and Andrew Griffiths for technical support. George Luther and Katherine Mullaugh at the University of Delaware supervised the voltammetric work in the US. Hiroaki Ohfuji assisted with the TEM work at Ehime University, Japan. Joachim Rinna, Michael O’Reilly, Carsten Muller, David Knight, Damian Dunford, Robert Jenkins, Elisa Lopez-Capel, David Manning, David Morgan and Albert Carley helped with the GC, NMR, TGA and XPS experiments. Kind help from Zhongfu Zhou and Zhigang Pan in Prof. Harris’ group and Zhongwen Yao at the University of Oxford on the solid state chemistry experiments is appreciated. I thank my friend Qi Wang at UCLA for writing a PYTHON program which enabled me to process the XRPD data. Many thanks to my friends in Cardiff, especially Min, Siyuan and Eezhuan for sharing my joys, as well as listening to the grumbles. I value the friendship with the fellow students in the School: Sarah, Paivi, Julia, Wendy, Anna, Bryan, Alan, Martin, Cathal and Dave. They brought me much happiness outside of work. Special thanks to my flatmates at Talybont South, Miao and Xurui for teaching me to shop and cook. Finally, I greatly thank my parents Fubin Huang and Fengzhen Ding, who went through this course with me all the time and who give me a warm home in Wuhan where I can always return. ii Contents A bstract................................................................................................................................................................i Acknowledgements .........................................................................................................................................ii C ontents ............................................................................................................................................................. iv Chapter 1 Introduction...................................................................................................................1 1.1 Background .........................................................................................................................2 1.2 Project a im s ........................................................................................................................5 1.3 Thesis sum m ary................................................................................................................ 5 Chapter 2 Nickel Sulfide: Mineralogy and Chemistry............................................................. 7 Figures and tables .................................................................................................................... 8 A bstract.......................................................................................................................................9 2.1 Introduction ....................................................................................................................... 9 2.1.1 Overview ................................................................................................................. 9 2.1.2 Nickel sulfides ......................................................................................................10 2.1.3 Nomenclature ........................................................................................................ 13 2.2 Nickel monosulfide: millerite .....................................................................................14 2.2.1. M illerite structure.............................................................................................14 2.2.2 Millerite composition .........................................................................................14 2.2.3 Millerite formation ............................................................................................. 15 2.2.4 Electronic and other properties ........................................................................16 2.3 NiAs-type N iS .................................................................................................................16 2.3.1 NiAs-type NiS structure ................................................................................... 20 2.3.2 NiAs-type NiS composition ............................................................................. 21 2.3.3 NiAs-type NiS formation .................................................................................. 21 2.3.4 Electronic properties ...........................................................................................22 2.4 Nickel thiospinel, polydymite .....................................................................................22 2.4.1 Polydymite structure ...........................................................................................22 2.4.2 Polydymite com position....................................................................................23