Visible-light-driven　H2　production　from　pure　water　is　highly　promising　but　unfortunately　inefficient.　Herein,　for　the　first　time,　we　report　the　realization　of　pure-water-splitting　H2　production　under　visible-light　irradiation　via　single-component　CdS　without　any　cocatalysts,　employing　a　piezoelectric-photocatalysis　strategy.　Wurtzite　CdS　nanorod　arrays　that　combine　piezoelectric　and　visible-light　photocatalytic　properties　was　in-situ　assembled　on　FTO　substrates　to　harvest　both　solar　energy　and　ultrasonic　vibration　energy　in　water.　The　ultrasound-induced　piezoelectric　field　in　CdS　drives　the　separation　of　photo-generated　charge　carriers,　leading　to　more　facile　water-splitting　for　H2　evolution　than　that　under　visible-light　irradiation　alone.　The　CdS　nanorod　arrays　achieves　a　high　H2　production　rate　of　20　μL.h−1　under　optimized　coupling　field,　which　is　much　higher　than　that　of　unsupported　samples.　This　work　demonstrates　the　capability　of　piezoelectric　photocatalysts　to　simultaneously　convert　visible　light　energy　and　acoustic　energy　into　hydrogen　energy,　which　may　break　a　new　ground　for　the　design　of　energy-conversion　materials　towards　harvesting　discrete　ambient　energy　in　urban　environment.　©　2018　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim