Formal and positive. Pairs with abstract, high-minded objects: 真理, 理想, 目标, 事业, 完美. Not used for trivial everyday pursuits.
memory
孜孜 is a reduplicative meaning 'diligent, tireless' — mimics the quiet hum of persistent effort. 以求 = 'in order to seek'. Whole phrase: 'diligently seeking'.