Fabrication　of　low-dimensional　nano-MOFs　as　well　as　nanoparticles/metal-organic　frameworks　(MOFs)　hybrids　has　sparked　new　scientific　interests　but　remains　a　challenging　task.　Taking　Cu3(BTC)2　as　a　proof　of　concept,　it　is　demonstrated　thats　NH3⋅H2O　solution　of　a　confined　pH　value　can　readily　shape　the　bulk　Cu3(BTC)2　into　nanoscale　Cu3(BTC)2,　beyond　the　need　to　control　the　crystal　growth　kinetics　of　MOFs.　Adjusting　the　pH　of　NH3⋅H2O　within　a　much　small　range　(10–11)　allows　fine　tuning　over　the　size　and　shape　of　nanoscale　Cu3(BTC)2.　Particularly　at　pH　=　11,　NH3⋅H2O　exhibits　weak　reducibility　that　triggers　a　reduction　of　part　of　Cu3(BTC)2　into　Cu2O,　while　shaping　the　other　into　Cu3(BTC)2　nanowires.　Benefiting　from　the　coincidence　of　reduction　and　etching　effects,　the　newly　generated　Cu2O　dots　can　in　situ　anchor　onto　adjacent　Cu3(BTC)2　nanowires　at　highly　dispersive　state,　forming　a　well-defined　sponge-like　architecture　built　of　Cu2O　dots　and　nano-Cu3(BTC)2.　The　CuOx　derived　from　annealing　of　the　Cu2O　dots/nano-Cu3(BTC)2　hybrid　preserves　the　sophisticated　sponge　architecture　and　high　porosity,　and　exhibits　promising　applications　in　phenol　scavenging,　with　efficiency　outperforming　its　counterparts　and　many　other　Cu-based　catalysts　reported　in　literature.　It　is　anticipated　that　the　findings　here　pave　the　way　for　the　rational　design　of　intricate　nano-MOFs　in　a　more　efficient　way.　©　2019　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim