To　enhance　the　efficiency　of　photocatalytic　H2　evolution,　numerous　methods　are　employed　by　increasing　the　utilization　of　photogenerated　charge　carriers　(PCCs),　including　catalyst　design,　defect　regulation,　and　selection　of　suitable　H+　resources.　Using　self-assembly　method,　CoWO4/ZnxCd1−xS　with　p–n　heterojunction　was　synthesized.　Although　CoWO4　(CW)　cannot　produce　H2　under　visible　light　irradiation,　it　can　provide　photogenerated　electrons　(e−)　to　Zn0.3Cd0.7S　(ZCS),　and　largely　increase　the　photocatalytic　activity　of　ZCS.　The　optimal　CW/ZCS　composite　can　reach　15.58　mmol·g−1·h−1,　which　is　45.8　and　24.3　times　higher　than　the　values　of　the　pure　CdS　and　ZCS,　respectively.　The　largely　enhanced　photocatalytic　H2　production　is　attributed　to　the　Zn　vacancies　(VZn),　p–n　heterojunction,　and　p-chlorobenzyl　alcohol　(Cl–PhCH2OH)　as　the　H+　source　of　H2　production.　VZn　on　the　ZCS　surface　as　the　capture　center　of　photogenerated　holes　(h+),　can　regulate　the　carrier　distribution,　which　results　in　more　photogenerated　e−　and　less　generated　h+.　The　combination　of　p–n　heterojunction　and　VZn　can　enhance　the　separation　and　transfer　efficiency　of　PCCs,　and　effectively　inhibit　the　recombination　of　charge　carriers.　To　further　improve　the　utilization　rate　of　PCCs,　the　photocatalytic　H2　evolution　is　proceeded　by　Cl–PhCH2OH　oxidation　in　N,N-dimethylformamide　solution,　with　4-chlorobenzaldehyde　(Cl–PhCHO)　generated.　The　separated　photogenerated　e−　and　h+　both　participated　in　the　redox　reaction　of　H+　reduction　and　Cl–PhCH2OH　oxidation,　considering　that　the　amount　of　H2　and　Cl–PhCHO　products　are　close　to　1:1.　This　work　not　only　facilitates　the　separation　and　transfer　of　PCCs,　but　also　provides　directions　for　the　design　of　efficient　photocatalysts　and　H2　evolution　in　the　organic　phase.　©　2024　Elsevier　Inc.